Object (computer science)

About: Object (computer science) is a research topic. Over the lifetime, 106024 publications have been published within this topic receiving 1360115 citations. The topic is also known as: obj & Rq.

Mobile object locator

Abstract: There is disclosed a method and apparatus for an object locator system ( 10 ) for requesting and obtaining information about the location of a mobile object, having attached thereon a lightweight object locator ( 42 ), operable in a region served by a two-way paging system ( 12 ) and a global positioning satellite system ( 50 ). The object locator ( 42 ) may be selectively activated to conserve power or enabled to respond only when beyond or within a boundary. Further, the object locator system ( 10 ) may provide the location information in several forms including rectangular or polar coordinates referred to a base station ( 18 ) or origin, position on a map display, etc. In alternate embodiments the two-way paging system ( 12 ) may be substituted by a direct wireless link or a satellite relay communications link; the location information may be translated into human readable form either before or after transmission from the object locator; the location information may be presented at an output as selectable text, spoken message or graphic display including a map; the location information may have associated therewith other information such as time the location was determined, the status of the object locator, the condition of the battery, position of the object locator relative to a boundary or electronic fence or to indicate an alarm condition; or the location information may be accessed or delivered by dial-up or automatic means.

Object Fusion in Mediator Systems

Abstract: One of the main tasks of mediators is to fuse information from heterogeneous information sources. This may involve, for example, removing redundancies, and resolving inconsistencies in favor of the most reliable source. The problem becomes harder when the sources are unstructured/semistructured and we do not have complete knowledge of their contents and structure. In this paper we show how many common fusion operations can be specified non-procedurally and succinctly. The key to our approach is to assign semantically meaningful object ids to objects as they are “imported” into the mediator. These semantic ids can then be used to specify how various objects are combined or merged into objects “exported” by the mediator. In this paper we also discuss the implementation of a mediation system based on these principles. In particular, we present key optimization techniques that significantly reduce the processing costs associated with information fusion.

Virtual classes: a powerful mechanism in object-oriented programming

Abstract: The notions of class, subclass and virtual procedure are fairly well understood and recognized as some of the key concepts in object-oriented programming. The possibility of modifying a virtual procedure in a subclass is a powerful technique for specializing the general properties of the superclass.In most object-oriented languages, the attributes of an object may be references to objects and (virtual) procedures. In Simula and BETA it is also possible to have class attributes. The power of class attributes has not yet been widely recognized. In BETA a class may also have virtual class attributes. This makes it possible to defer part of the specification of a class attribute to a subclass. In this sense virtual classes are analogous to virtual procedures. Virtual classes are mainly interesting within strongly typed languages where they provide a mechanism for defining general parameterized classes such as set, vector and list. In this sense they provide an alternative to generics.Although the notion of virtual class originates from BETA, it is presented as a general language mechanism.

Realistic occlusion for a head mounted augmented reality display

Abstract: Technology is described for providing realistic occlusion between a virtual object displayed by a head mounted, augmented reality display system and a real object visible to the user's eyes through the display. A spatial occlusion in a user field of view of the display is typically a three dimensional occlusion determined based on a three dimensional space mapping of real and virtual objects. An occlusion interface between a real object and a virtual object can be modeled at a level of detail determined based on criteria such as distance within the field of view, display size or position with respect to a point of gaze. Technology is also described for providing three dimensional audio occlusion based on an occlusion between a real object and a virtual object in the user environment.

Access control and authorization system

Abstract: A process of encrypting an object includes applying a hash algorithm to the object, generating a random number, combining a first plurality of splits including the random number to form a working split, encrypting the object using the working split, combining a second plurality of splits not including the random number to form a value, encrypting the random number using the value, encrypting the hashed object according to a signature algorithm using a user private key, encrypting the hashed object according to a selected algorithm using the working split as a key, forming a header including information that can be used to decrypt the object, encrypting the header, and adding the encrypted header to the encrypted object. The pluralities of splits include a fixed split, a variable split, and a label split corresponding to a selected label. The header includes the encrypted random number, a label, and a digital signature.