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.

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.

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.

Abstract: A method of fabricating a needle via conformal deposition in a two-piece mold includes the step of attaching a top mold member to a bottom mold member such that the top mold member and the bottom mold member define an enclosed, elongated needle trench with a deposition aperture. A conformal substance, such as polysilicon, is then passed through the deposition aperture such that the conformal substance is deposited within the enclosed, elongated needle trench to form a needle. The method is used to form needles with prongs, multiple channels, multiple ports, barbs, strength enhancement features, and circuitry.

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.

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.

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.

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.

Abstract: A method of fabricating a needle via conformal deposition in a two-piece mold includes the step of attaching a top mold member to a bottom mold member such that the top mold member and the bottom mold member define an enclosed, elongated needle trench with a deposition aperture. A conformal substance, such as polysilicon, is then passed through the deposition aperture such that the conformal substance is deposited within the enclosed, elongated needle trench to form a needle. The method is used to form needles with prongs, multiple channels, multiple ports, barbs, strength enhancement features, and circuitry.

Abstract: This invention relates to the area of microelectromechanical systems in which electronic circuits and mechanical devices are integrated on the same silicon chip. The method taught herein allows the fabrication of thin film structures in excess of 150 microns in height using thin film deposition processes. Wafers may be employed as reusable molds for efficient production of such structures.

Abstract: A thin film filter fabricated using surface micromachining. The width of the filter pores is determined by the thickness of a sacrificial thin-film layer. This dimension can be precisely controlled, and may be as small as about 50 angstroms. The pore length may also be determined by the thickness of thin film layers and can therefore be smaller than the limit of resolution obtainable with photolithography. The filters are suitable for use at high temperatures and with many harsh solvents.

Abstract: The present invention provides a capsule made of a biologically compatible material with sufficient mechanical strength to form a very thin membrane shell having at least a region with approximately uniformly sized and spaced holes or pores that are large enough to let a desired biologically active molecular product through, while blocking the passage of all larger immunological molecules. The present invention thus provides an immunological isolation of cell transplants contained therein. The present invention also provides a free standing thin film structure that may be used as a component of such a capsule and method for the fabrication of such component and capsules.

Abstract: A modular construction member for the construction of decking, flooring, roofing, and the like, including a matable connector formed integrally with the construction member for connecting successive deck members to form a deck assembly. The modular construction member includes a gutter portion and a groove portion, which may be inter-connected to provide a substantially water-proof structure. A separate fastener may be passed through the gutter portion, the groove portion, and into a subfloor to further secure the structure and to withstand upward forces from, for example, wave action in a marine environment.

Abstract: This invention relates to the area of microelectromechanical systems in which electronic circuits and mechanical devices are integrated on the same silicon chip. The method taught herein allows the fabrication of thin film structures in excess of 150 microns in height using thin film deposition processes. Wafers may be employed as reusable molds for efficient production of such structures.

Abstract: A thin film filter fabricated using surface micromachining. The width of the filter pores is determined by the thickness of a sacrificial thin-film layer. This dimension can be precisely controlled, and may be as small as about 50 angstroms. The pore length may also be determined by the thickness of thin film layers and can therefore be smaller than the limit of resolution obtainable with photolithography. The filters are suitable for use at high temperatures and with many harsh solvents.

Abstract: This invention relates to the area of microelectromechanical systems in which electronic circuits and mechanical devices are integrated on the same silicon chip. The method taught herein allows the fabrication of thin film structures in excess of 150 microns in height using thin film deposition processes. Wafers may be employed as reusable molds for efficient production of such structures. Various material properties may be varied within the structures to produce electrical, mechanical or electromechanical devices.

Abstract: Method, with structure, of production of precision head/disk interfaces for near contact recording in a low viscosity liquid lubricant film. Triangular shaped bearing pads in an assembled hard drive are brought to bear upon a rotating lubricated disk to dislodge, smooth and polish any residing asperity. The triangular shape of the bearing pads sweeps away and directs to the outer edge of the disk any of the remaining fine carbon sputtering debris which is loosened as the bearing pads are drawn from the inner dimension to the outer dimension of the disk.

Abstract: The back edge of a disk drive slider is used to remove debris from disk media by slowly sweeping it from the inner diameter of the disk to the outer diameter of the disk while the disk is rotating backwards from normal. The sweeping operation is completed while the disks are still gaining rotational speed so that liftoff velocity is not achieved. Material accumulated on the back edge of the slider is either dumped at the outer diameter of the disk, or remains on the back edge of the slider as normal operation is commenced.

Abstract: The lubricant film for a near contact magnetic recording device is maintained by a closed loop servo control for a recirculating lubricant supply system. A reservoir closely overlies the disk data surface and includes a heater for controlling the temperature difference between the reservoir and the disk surface. Decreasing the heater current reduces the film thickness and increasing the heater current increases the film thickness. A wick system gathers lubricant from within the disk enclosure, which may have been spun off the disk or condensed from the lubricant laden atmosphere and returns the lubricant by capillary action to the reservoir. Further, the reservoir includes two portions which are independently controllable. The first overlies the data band of the disk and the second overlies the start/stop zone and the head when the latter is not operational and parked at the nonoperating location.