Abstract: Hub based labeling is used, in databases, to determine a shortest path between two locations. Every point has a set of hubs: this is the label (along with the distance from the point to all those hubs). The hubs are determined that intersect the two labels. This information is used to find the shortest distance. A hub based labeling technique uses, in a database, a preprocessing stage and a query stage. Finding the hubs is performed in the preprocessing stage, and finding the intersecting hubs is performed in the query stage using relational database operators, such as SQL queries. During preprocessing, a forward label and a reverse label are defined for each vertex. The labels are generated using contraction hierarchies that may be guided by shortest path covers. A query, such as an SQL query, is processed using the labels to determine the shortest path.

Abstract: Hub based labeling is used to determine a shortest path between two locations. Every point has a set of hubs: this is the label (along with the distance from the point to all those hubs). The hubs are determined using the labels. The hubs are determined that intersect the two labels, and this information is used to find the shortest distance. A hub based labeling technique uses a preprocessing stage and a query stage. Finding the hubs is performed in the preprocessing stage, and finding the intersecting hubs (i.e., the common hubs they share) is performed in the query stage. During preprocessing, a forward label and a reverse label are defined for each vertex. The labels are generated using contraction hierarchies that may be guided by shortest path covers, and may be pruned. A query is processed using the labels to determine the shortest path.

Abstract: Graph partitioning techniques are based on the notion of natural cuts. A filtering phase performs a series of minimum cut computations to identify and contract dense regions of the graph. This reduces the graph size significantly, but preserves its general structure. An assembly phase uses a combination of greedy and local search heuristics to assemble the final partition. The techniques may be used on road networks, which have an abundance of natural cuts (such as bridges, mountain passes, and ferries).

Abstract: The non-negative single-source shortest path (NSSP) problem is solved on a graph by using a preprocessing phase and then, in a query phase, computing the distances from a given source in the graph with a linear sweep over all the vertices. Contraction hierarchies may be used in the preprocessing phase and in the query phase. Optimizations may include reordering the vertices in advance to exploit locality, performing multiple NSSP computations simultaneously, marking vertices during initialization, and using parallelism. Techniques may be performed on a graphics processing unit (GPU). This makes applications based on all-pairs shortest-paths practical for continental-sized road networks. The applications include, for example, computing graph diameter, exact arc flags, and centrality measures such as exact reaches or betweenness.

Abstract: Alternative routes to an optimal route may be determined and presented to a user via a computing device. Alternative routes are selected from candidate routes that meet admissibility criteria. In an implementation, admissibility of a candidate route (in order for it to be considered an alternative route) may be determined based on three criteria: “limited sharing”, “local optimality”, and “stretch” such as “uniformly bounded stretch”. Limited sharing refers to the amount of difference between the alternative route and the optimal route, local optimality refers to lack of unnecessary detours, and uniformly bounded stretch refers to a length of the shortest path to travel between two points on the alternative route.

Abstract: Some of the embodiments provided herein disclose receiving a plurality of bids, each bid being submitted by a bidder, and each bid having a bid value; assigning a weighting factor to each bid, the weighting factor being based, at least in part, on the bid value; selecting a first bid from the plurality of bids, the first bid having been submitted by a first bidder; selecting a second bid from the plurality of bids, the second bid being selected in a manner that is dependent, at least in part, on the weighting factor assigned to the second bid; performing a comparison of the value of the first bid with the value of the second bid; using the results of the comparison to determine whether to vend a copy of the digital file to the first bidder; and sending a copy of the digital file to the first bidder.

Abstract: The present invention provides for generating inputs that can be provided to a message classification module to facilitate more reliable classification of electronic messages, such as, for example, as unwanted and/or unsolicited. In one embodiment, a sending messaging server provides an appropriate response to address verification data thereby indicating a reduced likelihood of the sending messaging server using a forged network address. In another embodiment, it is determined if a messaging server is authorized to send electronic messages for a domain. In yet another embodiment, electronic message transmission policies adhered to by a domain are identified. In yet a further embodiment, a sending computer system expends computational resources to solve a computational puzzle and includes an answer document in an electronic message. A receiving computer system receives the electronic message and verifies the answer document.

Abstract: An algorithm referred to as REAL for the point-to-point shortest path problem combines A* search with landmark-based lower bounds and reach-based pruning. A symbiosis of these techniques is described, which gives a range of time and space tradeoffs, including those that improve both of these complexity measures. Locality is improved and exact reach computation is described.

Abstract: Methods and systems are described for computing shortest paths among a set of locations. A small set of landmarks is chosen and the distance between each location and each landmark is computed and stored. Given source and destination locations, the landmark distances are used to compute lower-bound estimates of distances from locations to the destination. The estimates are then used with a heuristic search to find the shortest path from source to destination.

Abstract: A set of landmarks may be selected during preprocessing by evaluating a sample of the queries that the landmarks may be used in. A cost function may be used to generate a k-median problem. The k-median problem may then be solved with heuristics. The landmarks may then be used with A* search to find the shortest path from a source to a destination.

Abstract: The present invention provides for generating inputs that can be provided to a message classification module to facilitate more reliable classification of electronic messages, such as, for example, as unwanted and/or unsolicited. In one embodiment, a sending messaging server provides an appropriate response to address verification data thereby indicating a reduced likelihood of the sending messaging server using a forged network address. In another embodiment, it is determined if a messaging server is authorized to send electronic messages for a domain. In yet another embodiment, electronic message transmission policies adhered to by a domain are identified. In yet a further embodiment, a sending computer system expends computational resources to solve a computational puzzle and includes an answer document in an electronic message. A receiving computer system receives the electronic message and verifies the answer document.

Abstract: The present invention provides for generating inputs that can be provided to a message classification module to facilitate more reliable classification of electronic messages, such as, for example, as unwanted and/or unsolicited. In one embodiment, a sending messaging server provides an appropriate response to address verification data thereby indicating a reduced likelihood of the sending messaging server using a forged network address. In another embodiment, it is determined if a messaging server is authorized to send electronic messages for a domain. In yet another embodiment, electronic message transmission policies adhered to by a domain are identified. In yet a further embodiment, a sending computer system expends computational resources to solve a computational puzzle and includes an answer document in an electronic message. A receiving computer system receives the electronic message and verifies the answer document.

Abstract: An algorithm referred to as REAL for the point-to-point shortest path problem combines A* search with landmark-based lower bounds and reach-based pruning. A symbiosis of these techniques is described, which gives a range of time and space tradeoffs, including those that improve both of these complexity measures. Locality is improved and exact reach computation is described.

Abstract: Systems and methods are provided for pricing, selling, and/or otherwise distributing electronic content using auction mechanisms. A randomized auction mechanism is used to determine both the number of goods that are sold and the selling price. The auction mechanism automatically adapts to the bid distribution to yield revenue that is competitive with that which could be obtained if the vendor were able to determine the optimal fixed price for the goods. In one embodiment a set of bids is randomly or quasi-randomly partitioned into two or more groups. An optimal threshold is determined for each group, and this threshold is then used to select winning bids from one or more of the other groups. In another embodiment, each bid is compared to a competing bid that is randomly or quasi-randomly selected from the set of bids. If the bid is less than the randomly-selected competing bid, the bid is rejected. Otherwise, the bid is accepted and the bidder buys the auctioned item at the price of the randomly-selected bid.

Abstract: The present invention provides for generating inputs that can be provided to a message classification module to facilitate more reliable classification of electronic messages, such as, for example, as unwanted and/or unsolicited. In one embodiment, a sending messaging server provides an appropriate response to address verification data thereby indicating a reduced likelihood of the sending messaging server using a forged network address. In another embodiment, it is determined if a messaging server is authorized to send electronic messages for a domain. In yet another embodiment, electronic message transmission policies adhered to by a domain are identified. In yet a further embodiment, a sending computer system expends computational resources to solve a computational puzzle and includes an answer document in an electronic message. A receiving computer system receives the electronic message and verifies the answer document.