Abstract: In a method for rendering an evolving three-dimensional scene description as a series of two-dimensional images (frames), the evolving scene description includes object geometries G and their associated shader procedures S. Each shader procedure S is factored into a static procedure Ss and a dynamic procedure Sd such that S(A,I)=Sd(Ss(A,R),I), where A denotes the appearance parameters required to shade objects, I denotes an instance of the control parameters, and R denotes a range of control parameters which include I. Similarly, the rendering procedure TSI (transform, sample, and interpolate) for object geometry is factored into a static procedure TSIs and a dynamic procedure TSId such that TSI(G,I)=TSId(TSIs(G,R),I). The factorization of both S and TSI is chosen to significantly reduce the overall rendering time for the evolving scene.

Abstract: The casting assembly includes a horseshoe shaped casting ring having a plurality of handling posts; a horseshoe shaped crucible former having a flange for retaining the casting ring and a top surface for supporting the casting ring; and a pair of tongs having a plurality of openings, each of the openings adapted to receive one of the handling posts.

Abstract: A system for fast, efficient and reliable communication of object state irmation among a group of processes combines the use of a fast, but lossy and thus unreliable communications channel to the group of processes and a server coupled to the group for providing data which has been lost in the multicasting. In one embodiment, a central server supports reliability and rapid joining while using UDP multicast messaging to achieve rapid interaction and low bandwidth. Differential messages are sent over the lossy channel to compactly describe how to compute the new state of an object from any of several previous states. Such a description can be interpreted even if some number of prior descriptions were not received, greatly reducing the need for explicit, round-trip message repairs while also conserving bandwidth. In one embodiment, the central server communicates with each member of the group over a reliable channel to robustly detect and repair objects affected by lost messages.

Abstract: In a multicast environment in which large-scale virtual environments are lt using locales and in which data from non-neighboring locales is ignored to minimize computation and local storage, a system is provided to find or track objects and their associated locales for locales to which a user is not listening by assigning the object a beacon and broadcasting the beacon in a subspace channel, with the beacon having the multicast address of the locale in which the sought-after object resides, thus to permit an upload of data from the particular locale. Beacons are doled out parsimoniously to objects one wants to find and objects one wants other people to find to minimize processing and data storage requirements. Ignored locales are thus located using a beacon broadcast in a subspace channel which in addition to broadcasting messages about itself to the locale it is in, also broadcasts messages into a subspace channel to others about itself and the multicast address of the locale it is in.

Abstract: A system is provided for eliminating time-consuming, unnecessary transfers f data over networks such as the the World Wide Web while at the same time guaranteeing timeliness of the data used by recipients. Timeliness is assured by immediately sending small data-notification messages whenever data becomes relevant or changes. Efficiency is guaranteed by transmitting the data itself only when requested by the recipient of a data-notification message. In particular, recipients are alerted to the presence of, and changes in, data they might use by data-notification messages containing a timestamp, the data location, and a checksum. Based on the timestamp, the recipient can determine whether the data-notification message contains timely information or should be ignored. Based on the data location and checksum, the recipient can determine whether it already has the current version of the data in question, for example stored in a cache.

Abstract: A system assures smooth motion in a distributed virtual reality environment y categorizing the information to be transmitted as to the predictability of future motion and applying appropriate smoothing algorithms based upon knowledge of what the future motion is likely to be. The system switches between a linear interpolation algorithm for less predictable data and a Catmull-Rom spline for more predictable data.

Abstract: A system for virtual environments in which graphical objects are depicted in a space to achieve the required high accuracy regardless of location through establishing locales or subdivisions of the global coordinate system and establishing an origin for each locale, such that the specification of position and movement of a graphical object in the locale can be made with greater precision than using a global coordinate system, thus eliminating the need for high-precision floating point processors or emulation. The system permits designers of virtual environments to work independently on their locales, with overlap being controlled through specifying distance between locale origins as well as relative orientation between the locales. The system also permits ignoring information from non-relevant distant locales to, minimize processing and network bandwidth requirements.

Abstract: An all-audio, hands-free and eyes-free interactive tutor provides time-efficient and reduced-boredom instruction by varying a course of instruction based on the correct and incorrect responses of the user so as to frequently repeat and provide positive feedback for poorly-learned items of knowledge, to periodically refresh well-learned items and to suggest that rest be taken or to switch to easier material whenever too many human errors have occurred. The audio interactive tutor includes an audio input module, in the preferred embodiment a voice recognition unit based on a finite state grammar, an audio output module, a course of study and a user model. In a preferred embodiment, the course of study provides for human error control as well as for voice recognition unit error control, which synergistically cooperate to render the tutor substantially fault-tolerant and therewith enables the employment of commercially-available but not excessively accurate voice recognition units.

Abstract: A model of a human abdominal wall for use in demonstrating or practicing the use and maintenance of percutaneous endoscopic gastrostomy tubes. The model includes two or more layers bound together, the top or "external" layer approximating the feel and texture of human skin. The second layer approximates the feel and resistance of the subcutaneous tissues in the human abdominal wall. A third layer may be added, approximating the feel and resistance of human stomach tissue. Openings are provided which pass completely through the model to accommodate placement of percutaneous endoscopic gastrostomy tubes.

Abstract: A system is provided for dramatically decreasing the time required to parse a sentence by automatically converting a context-free grammar into a lexicalized form called lexicalized context-free grammar (LCFG) which is used in the parsing process. Lexicalized context-free grammar employs adjoining but, to decrease parsing time, only allows non-wrapping adjoining. The lexicalized context-free grammar is parsed using a parser that decreases parsing time by filtering the grammar based on the words in a sentence and maintaining the valid prefix property while parsing.

Abstract: An inking apparatus is provided for applying ink to a rotating roller of a printing press. The apparatus includes an ink fountain located adjacent the roller for applying ink to the roller, a doctor blade holder, and a doctor blade coupled to the doctor blade holder for engaging the roller with a predetermined pressure to scrape excess ink from the roller as the roller rotates relative to the doctor blade. The apparatus also includes first and second guide rails configured to define a slot therebetween for receiving the doctor blade holder therein, and a mechanism for retaining the doctor blade holder in the slot to hold the doctor blade against the roller during rotation of the roller.

Abstract: A high brilliance step-cut gem stone is formed by cutting natural or man-made gem stone material at a cutting angle of 90.degree. along respective cutting machine indices of 96, 48, 72 and 24 to form a rectangular block and then shaping the rectangular block by cutting the block along respective indices 94, 2, 50, 46, 70, 74, 26 and 22, to define an octagonal prism. The pavilion portion of the stone is formed by cutting a plurality of pavilion facets in stepped increments along each of the indices 94, 2, 50, 46, 70, 74, 26 and 22. A first group of pavilion facets defining the culet is cut at the critical angle of the material and each successive group of facets is cut in successive stepped increments of 6.degree. relative the critical angle, up to the girdle. A plurality of crown facets are also cut in stepped increments along each of the indices 94, 2, 50, 46, 70, 74, 26 and 22, upwardly from the girdle to define a relatively flat table at the top of the stone.

Abstract: An aerosol dispensing device for discharging a metered amount of medication-containing aerosol into the mouth of a patient by manual compression thereof, which effectively times the release of the medication containing aerosol to coincide with the onset of inhalation of the patient to more effectively introduce the medication deeply into the patient's lungs.