Patents by Inventor Karel Zikan

Karel Zikan 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: 7050053
    Abstract: A system for performing visible object determination. Visualization software executing on one or more processors searches a cone tree with respect to a hull tree. Both trees respect the same group of transformations. Thus, the cone tree as stored in memory need not store all branches down to ultimate resolution. For example, the cone tree may store a selected cone and all its subcones down to the ultimate resolution, while subcones of other cones at the same level as the selected cone may not be represented in the stored cone tree. When the visualization software encounters a nonstored cone and a given hull H in its search procedure, the visualization software may apply an appropriate one of the group transformations to the given hull, and search the tranformed hull with respect to the selected cone (or a subcone of the selected cone).
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: May 23, 2006
    Assignee: Sun Microsystems, Inc.
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Patent number: 7020147
    Abstract: A spontaneous data communication network includes antenna/transceiver sets located in mobile (e.g., vehicles such as cars, buses, trucks, ferries, etc.) or stationary units (e.g., computers, manufacturing equipment, office furniture, office equipment, road signs, overpasses, bridges, etc.). Each antenna/transceiver set directs network traffic based on optimizing a merit function or penalty function to reduce costs of congestion for stochastically changing demands and flows in a data communication system. The routers exchange values with neighboring routers. Based on the exchanged values and values local to a router, flow conditions are checked and if necessary the local values are adjusted until the flow conditions are satisfied or a time period expires. Adjustments are associated with optimizing a merit function or penalty function.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: March 28, 2006
    Assignee: Terabeam Corporation
    Inventors: Gregory Amadon, Henry Adam Sowizral, Karel Zikan
  • Patent number: 7006954
    Abstract: One embodiment of the present invention generates random samples for a Bernoulli distribution. A first covariance matrix is generated using a desired mean vector and a desired covariance matrix of the Bernoulli distribution. A normal vector is constructed using the desired mean vector and the first covariance matrix. A sampling vector is generated using the normal vector and a threshold vector. The sampling vector has the desired mean vector and the desired covariance matrix.
    Type: Grant
    Filed: February 15, 2002
    Date of Patent: February 28, 2006
    Assignee: Terabeam Corporation
    Inventors: Wendell Curtis, Karel Zikan, Henry Sowizral
  • Patent number: 6983283
    Abstract: A system and method that manages scene graphs by data staging is contemplated. Data staging entails selectively loading only the portions of the scene graph that are currently needed or likely to be needed in the near future. Other objects in the scene graph that are not currently needed or likely to be needed may be replaced by pointers. The pointers may point to the location from which the objects may be accessed if necessary for a future frame. The replaced portions of the scene graph may be compressed and/or cached to a local memory device (e.g., a local array of read-write optical drives) capable of storing large amounts of data, with the pointers indicating where the objects are stored.
    Type: Grant
    Filed: October 3, 2001
    Date of Patent: January 3, 2006
    Assignee: Sun Microsystems, Inc.
    Inventors: Henry Sowizral, Karel Zikan, Randall Keller
  • Publication number: 20040260813
    Abstract: An embodiment of the present invention includes a method to generate a network design. Candidate hubs for a wireless network are generated from a database of available hubs using a first set of criteria. A service level availability (SLA) is associated to each of the candidate hubs using a second set of criteria. A set of network configurations is generated from the candidate hubs. Each of the network configurations maximizes customer coverage and satisfies the associated SLA.
    Type: Application
    Filed: September 30, 2002
    Publication date: December 23, 2004
    Inventors: Jeff A. Heisserman, Christopher Esposito, Karel Zikan, Raju S. Mattikalli
  • Patent number: 6750859
    Abstract: A system for performing visible object determination. Visualization software running on a host processor represents space with a hierarchy of cones, and generates a hierarchy of bounding hulls from a collection of objects by recursively grouping clusters of objects. Each hull node in the hull hierarchy stores parameters which characterize a bounding hull for the corresponding cluster or object. The visualization software searches the cone and hull hierarchies starting with the root cone and the root hull. Before exploring a given cone-hull pair, a normalized cone size for the cone and a normalized hull size for the hull may be computed, and the sizes compared. If the cone size is larger than the hull size, subcones of the cone are explored with respect to the hull. Conversely, if the hull size is larger than the cone size, subhulls of the hull are explored with respect to the cone.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: June 15, 2004
    Assignee: Sun Microsystems, Inc.
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Patent number: 6731304
    Abstract: A system and method for determining graphical object visibility by utilizing ancillary geometry. When comparing visibility cones with bounding hulls of scene graph hierarchy leaf nodes, ancillary geometry may be used in place of the bounding hulls and the leaf node's actual geometry. The ancillary geometry may be created through a manual process, or by an automated decimation process. The ancillary geometry may be a simplistic analytic surface (e.g., a sphere or a cylinder), a NURB surface, a collection of polygons, or a combination of surfaces and polygons.
    Type: Grant
    Filed: December 6, 2001
    Date of Patent: May 4, 2004
    Assignee: Sun Microsystems, Inc.
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Publication number: 20030160776
    Abstract: A system for performing visible object determination. Visualization software executing on one or more processors searches a cone tree with respect to a hull tree. Both trees respect the same group of transformations. Thus, the cone tree as stored in memory need not store all branches down to ultimate resolution. For example, the cone tree may store a selected cone and all its subcones down to the ultimate resolution, while subcones of other cones at the same level as the selected cone may not be represented in the stored cone tree. When the visualization software encounters a nonstored cone and a given hull H in its search procedure, the visualization software may apply an appropriate one of the group transformations to the given hull, and search the tranformed hull with respect to the selected cone (or a subcone of the selected cone).
    Type: Application
    Filed: January 30, 2002
    Publication date: August 28, 2003
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Publication number: 20030065668
    Abstract: A system and method that manages scene graphs by data staging is contemplated. Data staging entails selectively loading only the portions of the scene graph that are currently needed or likely to be needed in the near future. Other objects in the scene graph that are not currently needed or likely to be needed may be replaced by pointers. The pointers may point to the location from which the objects may be accessed if necessary for a future frame. The replaced portions of the scene graph may be compressed and/or cached to a local memory device (e.g., a local array of read-write optical drives) capable of storing large amounts of data, with the pointers indicating where the objects are stored.
    Type: Application
    Filed: October 3, 2001
    Publication date: April 3, 2003
    Inventors: Henry Sowizral, Karel Zikan, Randall Keller
  • Publication number: 20020191034
    Abstract: A system for performing visible object determination. Visualization software running on a host processor represents space with a hierarchy of cones, and generates a hierarchy of bounding hulls from a collection of objects by recursively grouping clusters of objects. Each hull node in the hull hierarchy stores parameters which characterize a bounding hull for the corresponding cluster or object. The visualization software searches the cone and hull hierarchies starting with the root cone and the root hull. Before exploring a given cone-hull pair, a normalized cone size for the cone and a normalized hull size for the hull may be computed, and the sizes compared. If the cone size is larger than the hull size, subcones of the cone are explored with respect to the hull. Conversely, if the hull size is larger than the cone size, subhulls of the hull are explored with respect to the cone.
    Type: Application
    Filed: June 28, 2001
    Publication date: December 19, 2002
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Publication number: 20020163515
    Abstract: A system and method for determining graphical object visibility by utilizing ancillary geometry. When comparing visibility cones with bounding hulls of scene graph hierarchy leaf nodes, ancillary geometry may be used in place of the bounding hulls and the leaf node's actual geometry. The ancillary geometry may be created through a manual process, or by an automated decimation process. The ancillary geometry may be a simplistic analytic surface (e.g., a sphere or a cylinder), a NURB surface, a collection of polygons, or a combination of surfaces and polygons.
    Type: Application
    Filed: December 6, 2001
    Publication date: November 7, 2002
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Publication number: 20020158856
    Abstract: A system and method for rendering and displaying 3D objects. The system comprises a rendering unit coupled to a sample buffer and one or more convolve units. The rendering unit is configured to receive vertices of a triangle. The vertices are presented as coordinate pairs with respect to coordinate axes of a virtual screen space. The virtual screen space may be partitioned into bins. The rendering unit selects a set of candidate bins (i.e. bins which because of their positional relation to the triangle may contribute samples to the triangle), and generates a collection of sample positions within the candidate bins.
    Type: Application
    Filed: September 11, 2001
    Publication date: October 31, 2002
    Inventors: Michael F. Deering, Karel Zikan
  • Patent number: 6445391
    Abstract: A system and method for performing visible object determination based upon a dual search of a cone hierarchy and a bounding (e.g. hull) hierarchy. Visualization software running on a host processor represents space with a hierarchy of cones constructed by recursive refinement, and represents a collection of objects with a hierarchy of bounding hulls. The visualization software searches the cone and hull hierarchies starting with the root cone and the root hull. Before exploring a given cone-hull pair, a cone-restricted minimum distance between the cone and the hull is measured and compared to the visibility distance value of the cone. Only when the former is smaller than the latter will the cone be searched against the hull.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: September 3, 2002
    Assignee: Sun Microsystems, Inc.
    Inventors: Henry Sowizral, Karel Zikan
  • Patent number: 6437796
    Abstract: A system and method for performing visible object determination based upon a dual search of a cone hierarchy and a bound hierarchy performed by multiple processors. Each processor is configured to read a (global and/or local) problem queue to access a bound-cone pair. The bound-cone pair points to a bound in the bound hierarchy and a cone in the cone hierarchy. The processor computes a bound-cone distance between the bound and the cone, and compares the bound-cone distance to a visibility distance associated with the cone. If the bound-cone distance is smaller than the visibility distance, the processor may write two or more refined bound-cone pairs corresponding to a refinement of the original pair to the global or local problem queue. When the processor detects a leaf bound and a leaf cone, it updates a nearest object pointer and the visibility distance associated with the leaf cone.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: August 20, 2002
    Assignee: Sun Microsystems, Inc.
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Publication number: 20020050990
    Abstract: A system and method for performing visible object determination based upon a dual search of a cone hierarchy and a bounding (e.g. hull) hierarchy. Visualization software running on a host processor represents space with a hierarchy of cones constructed by recursive refinement, and represents a collection of objects with a hierarchy of bounding hulls. The visualization software searches the cone and hull hierarchies starting with the root cone and the root hull. Before exploring a given cone-hull pair, a cone-restricted minimum distance between the cone and the hull is measured and compared to the visibility distance value of the cone. Only when the former is smaller than the latter will the cone be searched against the hull.
    Type: Application
    Filed: October 9, 2001
    Publication date: May 2, 2002
    Inventors: Henry Sowizral, Karel Zikan
  • Patent number: 6373485
    Abstract: A system for determining nearest leaf bounds per leaf cone of a cone hierarchy based on a dual-tree search of the cone hierarchy and a bound hierarchy. A processor, performing the dual-tree search, maintains for each leaf cone a collection of nearest leaf bounds. The collection evolves as the dual-tree search progresses. The processor may maintain the N closest leaf bounds for each leaf cone. The processor may classify leaf bounds as occluders or non-occluders, and store any non-occluder closer than the Nth occluder. Alternatively, the processor may assign an occlusion metric value to each leaf bound, and may maintain closest leaf bounds so that the sum of their occlusion metric values is less than or equal to an occlusion threshold. The dual-tree search may be followed by a search of the bound hierarchy with probe cones of the leaf cones.
    Type: Grant
    Filed: June 27, 2001
    Date of Patent: April 16, 2002
    Assignee: Sun Microsystems, Inc.
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Publication number: 20020033835
    Abstract: A system for performing visible object determination. Visualization software running on a host processor represents space with a hierarchy of cones, and generates a hierarchy of bounding hulls from a collection of objects by recursively grouping clusters of objects. Each hull node in the hull hierarchy stores parameters which characterize a bounding hull for the corresponding cluster or object. The visualization software searches the cone and hull hierarchies starting with the root cone and the root hull. Before exploring a given cone-hull pair, a normalized cone size for the cone and a normalized hull size for the hull may be computed, and the sizes compared. If the cone size is larger than the hull size, subcones of the cone are explored with respect to the hull. Conversely, if the hull size is larger than the cone size, subhulls of the hull are explored with respect to the cone.
    Type: Application
    Filed: September 7, 2001
    Publication date: March 21, 2002
    Applicant: Sun Microsystems, Inc.
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Publication number: 20020000986
    Abstract: A system for determining nearest leaf bounds per leaf cone of a cone hierarchy based on a dual-tree search of the cone hierarchy and a bound hierarchy. A processor, performing the dual-tree search, maintains for each leaf cone a collection of nearest leaf bounds. The collection evolves as the dual-tree search progresses. The processor may maintain the N closest leaf bounds for each leaf cone. The processor may classify leaf bounds as occluders or non-occluders, and store any non-occluder closer than the Nth occluder. Alternatively, the processor may assign an occlusion metric value to each leaf bound, and may maintain closest leaf bounds so that the sum of their occlusion metric values is less than or equal to an occlusion threshold. The dual-tree search may be followed by a search of the bound hierarchy with probe cones of the leaf cones.
    Type: Application
    Filed: June 27, 2001
    Publication date: January 3, 2002
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Publication number: 20010055019
    Abstract: A system and method for performing visible object determination based upon a dual search of a cone hierarchy and a bound hierarchy performed by multiple processors. Each processor is configured to read a (global and/or local) problem queue to access a bound-cone pair. The bound-cone pair points to a bound in the bound hierarchy and a cone in the cone hierarchy. The processor computes a bound-cone distance between the bound and the cone, and compares the bound-cone distance to a visibility distance associated with the cone. If the bound-cone distance is smaller than the visibility distance, the processor may write two or more refined bound-cone pairs corresponding to a refinement of the original pair to the global or local problem queue. When the processor detects a leaf bound and a leaf cone, it updates a nearest object pointer and the visibility distance associated with the leaf cone.
    Type: Application
    Filed: June 29, 2001
    Publication date: December 27, 2001
    Inventors: Henry A. Sowizral, Karel Zikan, Randall G. Keller
  • Patent number: 6310881
    Abstract: In a data communication system having network traffic with flows, a network traffic director system using router modules. The router modules direct traffic based on optimizing a merit function or penalty function to reduce costs of congestion for stochastically changing demands and flows in the data communication system. The router modules exchange values with neighboring router modules. Based on the exchanged values and values local to a router module, flow conditions are checked and if necessary the local values are adjusted until the flow conditions are satisfied or a time period expires. Adjustments are associated with optimizing a merit function or penalty function. Based on the adjusted values, the router module adjusts parameters to be used to direct packets of the network traffic flows to other router modules or other destinations within the data communication system. An aggregation scheme is used for reducing the number of values stored in a single router module.
    Type: Grant
    Filed: October 20, 1998
    Date of Patent: October 30, 2001
    Assignee: Terabeam Corporation
    Inventors: Karel Zikan, Henry Adam Sowizral