摘要:
An architecture for a geographic database that supports the identification and use of names for intersections of roads located in a geographic region, and methods for use and formation thereof. The geographic database includes data that represent components of a road network in a geographic region. The geographic database includes a first plurality of data entities each of which represents an intersection of roads in the road network and a second plurality of data entities each of which represents a name of one of the components of the road network. The geographic database includes a third plurality of data entities each of which associates one of the first plurality of data entities with one of the second plurality of data entities. The third plurality of data entities are referenced by other data entities in the geographic database and by indices to allow a navigation application program using the geographic database to identify intersections of roads in the geographic region by name and to use the name of an intersection for the purpose of location identification and route guidance. Also disclosed is an improved process for forming substitute data records to represent complex physical geographic features thereby facilitating operation of a navigation system by reducing processing requirements for certain functions.
摘要:
A geographic database for use with a navigation application program that provides navigation features to an end-user. The geographic database includes a plurality of data records of a first type and a plurality of data records of a second type. The plurality of records of the first type are organized into a plurality of parcels, each of which includes a plurality of data records of the first type and the plurality of records of the second type are organized into a plurality of parcels, each of which includes a plurality of data records of the second type. The parcels of data records of the first type are interleaved with the parcels of data records of the second type. This interleaving enables navigation functions that use these different types to access these different types more quickly and efficiently, thereby enhancing navigation system performance. Also disclosed is a method for forming a geographic database that includes a plurality of data records that represent geographic features and which can be used in a navigation system. The method includes the step of interleaving parcels containing pluralities of data records of a first type with parcels containing pluralities of data records of a second type.
摘要:
A geographic database for use with a navigation application program that provides navigation features to an end-user. The geographic database includes data entities that represent segments of roads and additionally includes data entities that represent aggregations of segments of roads. The data entities that represent aggregations of segments of roads are used during a route calculation by the navigation application to suppress evaluation of roads of lesser functional rank thereby enhancing performance of the navigation system. According to one aspect, each of the data entities that represent segments of roads that represents a segment of a road that together with at least one other segment of a road forms part of an aggregation which is represented by one of the data entities that represent aggregations of segments of roads includes a reference thereto. According to another aspect, each of the data entities that represent aggregations of segments of roads refers to data entities that are abbreviated representations of the segments of roads included in the represented aggregation. Each of the data entities that are abbreviated representations of the segments of roads refers to a corresponding one of the data entities that represent segments of roads that represents the same respective segment of road. According to this aspect, at least some of the data entities that represent aggregations of segments of roads are stored separately from the data entities that are abbreviated representations of the segments of roads included in the represented aggregation. According to a further aspect, the navigation application program uses the references between the data entities that represent segments of roads, the data entities that represent aggregations of segments of roads, and the data entities that are abbreviated representations of the segments of roads included in the represented aggregation to provide navigation features, including evaluating which data entities to use for route calculation and ascertaining whether a solution route has been found.
摘要:
An improved method and system for storage of geographic data on physical storage media. The geographic data are stored in a manner that facilitates and enhances use and access of the data by various navigation application functions in navigation systems that use the data. The geographic data includes a parcelization that separates the geographic data into parcels having less than or equal to a maximum parcel size but having at least a desired fill percentage. The parcelization method also provides for a division arrangement that facilitates addressing and identification of the parcels. According to a further aspect, the geographic data includes special nodal entities that are used to collapse complex intersections, such as roundabouts, cloverleaves, and divided highways, into simpler data representations. The special nodal entities are associated with road segment data entities and used in a route calculation program in place of regular node entities. Further, the geographic data include a normalized attribute array that includes reoccurring combinations of certain selected attributes of the geographic data. Indices to the array are included in place of data corresponding to the selected attributes. When a navigation application program requests data, an entry in the normalized attribute table pointed to by an index in the data is used to return the requested data in the particular combination of attributes from the normalized attribute array. The geographic data is compiled by a method that facilitates access to the data on a physical medium. According to the compilation method, data files to be stored on the medium are organized into parcels. The data records within the data files are identified by the parcel in which they are located. An arrangement of all the data files on the medium is determined and a parcel identification related to the medium is assigned to each parcel. Cross references between data records are updated to include the assigned parcel identifications and the parcels are stored on the medium.
摘要:
An improved method and system for storage of geographic data on physical storage media. The geographic data are stored in a manner that facilitates and enhances use and access of the data by various navigation application functions in navigation systems that use the data. The geographic data includes a parcelization that separates the geographic data into parcels having less than or equal to a maximum parcel size but having at least a desired fill percentage. The parcelization method also provides for a division arrangement that facilitates addressing and identification of the parcels. According to a further aspect, the geographic data includes special nodal entities that are used to collapse complex intersections, such as roundabouts, cloverleaves, and divided highways, into simpler data representations. The special nodal entities are associated with road segment data entities and used in a route calculation program in place of regular node entities. Further, the geographic data include a normalized attribute array that includes reoccurring combinations of certain selected attributes of the geographic data. Indices to the array are included in place of data corresponding to the selected attributes. When a navigation application program requests data, an entry in the normalized attribute table pointed to by an index in the data is used to return the requested data in the particular combination of attributes from the normalized attribute array. The geographic data is compiled by a method that facilitates access to the data on a physical medium. According to the compilation method, data files to be stored on the medium are organized into parcels. The data records within the data files are identified by the parcel in which they are located. An arrangement of all the data files on the medium is determined and a parcel identification related to the medium is assigned to each parcel. Cross references between data records are updated to include the assigned parcel identifications and the parcels are stored on the medium.
摘要:
An improved method and system for storage of data that represent geographic features in a region. The data are organized into parcels each of which contains data that represent those geographic features that are located within a separate one of a plurality of rectangular areas into the region is divided. The method identifies linearly extending features that extend across multiple rectangular areas so that data representing the linearly extending feature can be included in each parcel that contains data that represents a rectangular area in which the linearly extending feature extends at least in part.
摘要:
A geographic database for use with a navigation application program that provides navigation features to an end-user. The geographic database includes a plurality of data records of a first type and a plurality of data records of a second type. The plurality of records of the first type are organized into a plurality of parcels, each of which includes a plurality of data records of the first type and the plurality of records of the second type are organized into a plurality of parcels, each of which includes a plurality of data records of the second type. The parcels of data records of the first type are interleaved with the parcels of data records of the second type. This interleaving enables navigation functions that use these different types to access these different types more quickly and efficiently, thereby enhancing navigation system performance. Also disclosed is a method for forming a geographic database that includes a plurality of data records that represent geographic features and which can be used in a navigation system. The method includes the step of interleaving parcels containing pluralities of data records of a first type with parcels containing pluralities of data records of a second type.
摘要:
A method of predicting the tendency of a heavy oil feed to generate coke deposits in the FCC riser under a given set of operating parameters in the unit; thus, by utilizing operating parameters appropriate to the feed, the formation of coke deposits in the riser may be minimized. The margin between the theoretical dew point of the hydrocarbon feed established from unit operating parameters and the theoretical mix zone temperature in the feed injection zone of the unit is developed by applying a regression-derived linear model from multiple rigorous model runs. The mix zone of the unit is then operated at a temperature which reduces the level of riser coking predicted from this ascertainable margin or, at least, maintains it within levels which are predictable and acceptable.
摘要:
A method for calculating a distance between a first point and a second point using linear interpolation is provided. The first point and the second point are located between a first latitude and a second latitude. An interpolated prime vertical radius of curvature value for a point between the first point and the second point is calculated based on a first prime vertical radius of curvature value for the first latitude and a second prime vertical radius of curvature value for the second latitude. An interpolated meridian radius of curvature value for the point between the first point and the second point is calculated based on a first meridian radius of curvature value for the first latitude and a second meridian radius of curvature value for the second latitude. An interpolated cosine value for the point between the first point and the second point is calculated based on a value representing a cosine of the first latitude and a value representing a cosine of the second latitude. The distance between the first point and the second point is then calculated based on the interpolated prime vertical radius of curvature value, the interpolated meridian radius of curvature value, and the interpolated cosine value. The use of interpolated prime vertical radius of curvature, meridian radius of curvature, and cosine avoids use of non-linear function evaluation. As a result, the process is efficient and the calculated distances are sufficiently accurate.
摘要:
A method and system for using data associated with a first vehicle and a given road segment defined for a road network and using data associated with a second vehicle and the given road segment to determine a multi-vehicle probability value that indicates a probability that the first vehicle and the second vehicle will arrive at a common position of the given road segment simultaneously. The multi-vehicle probability value can be compared to a threshold probability value to determine whether the first vehicle and/or the second vehicle should take a responsive measure to avoid those vehicles arriving at the common position of the given road segment simultaneously. The data associated the first vehicle and the data associated with the second vehicle can each include a respective electronic horizon for that vehicle, and time parameters and probability values associated with those vehicles being on the given road segment.