884 results about "Directed acyclic graph" patented technology

Each mobile router in an ad hoc mobile network is configured for concurrently attaching to multiple parents advertising respective parent depths relative to a clusterhead of the ad hoc mobile network. The mobile router selects an advertised depth relative to the clusterhead based on adding a prescribed increment to a maximum one of the parent depths, enabling the mobile routers to form a directed acyclic graph relative to the clusterhead. Each mobile router sends to each of its parents a neighbor advertisement message specifying at least one reachable prefix, a corresponding cost for reaching the reachable prefix, and a corresponding sequence identifier that enables the parents to validate the neighbor advertisement message relative to stored router entries. Hence, mobile routers automatically can form a directed acylic graph relative to the clusterhead, and can distribute routing information with minimal overhead.

Techniques for doing optimistic constraint checking in a versioned relational database system. The techniques find a subset of the versions of a table that contain all of the rows that need be checked for violation of a constraint when a given version is modified. When the versions of a table are organized into a directed acyclic graph (DAG), the subset for a given version is the ancestry of the given version, that is, the given version plus the ancestors of the given version in the DAG. Within the ancestry, the set of rows that must be checked is termed the version view. A row that belongs to the set has a primary key that is the latest version of the primary key in the given version's ancestry. The technique may be used for constraints including the referential integrity constraint and the unique key constraint. The metadata used to compute the version view is disclosed, as well as the manner in which the constraint checking techniques interact with the workspaces that provide access to the versions. The workspaces may be organized as a DAG. The manner in which the workspaces are organized determines how changes are propagated in the versioned relational database and thus the versions whose ancestry has to be checked for constraint violations.

The system has a collection of a plurality of objects. Each object defines a node in a k-partite graph, such that, the nodes can e divided into a number of mutually exclusive sets such that all of the nodes are in exactly one of the sets; further edges occur only between nodes in different sets; The system also has a simplification process that aggregates one or more of the nodes into one or more categories and identifies a category node corresponding to each category. The category node inherits the mode and the edges of all the nodes in the respective category. Further, the system contains Directed Acyclic Graphs Indices (DAGIs) whose nodes may have a 1-1 mapping with the nodes in the k-partite graph. These indices can be used to aggregate and hide nodes in the k-partite graph. Aggregation occurs by selecting one or more non-leaf nodes in the DAGI and aggregating all descendent nodes. Hiding occurs by selecting some set of DAGI nodes, thus selecting some corresponding set of nodes in the k-partite graph, and requesting this set of nodes be hidden which effectively removes them from further consideration until they are restored by explicit request.

Embodiments of the invention disclose a system and a method for determining a rank of a node in a multi-hop wireless network, wherein the network includes a gateway node, client nodes, and relay nodes, wherein a node p(i) is a default parent of the node i having a rank, and the network uses a directed acyclic graph (DAG) topology. The method comprises steps of transmitting at least one data packet from the node to the default parent node over a wireless link; counting a number of successful transmissions of most recent transmissions of data packets; determining an expected transmission time (ETX) for the wireless link based on the number of successful transmissions in the most recent transmissions; and assigning a rank R(i) to the node based on the rank of the parent node and the ETX.

Provided is a process that includes: traversing, with one or more processors, a constituency graph of a software asset and accessing corresponding trust records of a plurality of the software assets of the constituency graph visited by traversing the constituency graph, the trust records being published to a tamper-evident, immutable, decentralized data store; and for each respective constituent software asset among the plurality of constituent software assets visited by traversing, assessing, with one or more processors, trustworthiness of the respective software asset based on the corresponding trust record of the respective software asset.

The invention provides an ad hoc networks zone routing method. The method comprises an intra-domain routing work process and an inter-domain routing work process, a routing work process comprises an intra-domain routing discovery process and an intra-domain routing maintenance process, the intra-domain routing maintenance process is a recycling process, the intra-domain routing discovery process depends on the information maintained by the intra-domain routing maintenance process, the inter-domain routing work process comprises two steps: an inter-domain routing discovery process and an inter-domain routing maintenance process, the inter-domain routing maintenance process is a recycling process; the intra-domain routing maintenance process depends on a build process of an intra-domain directed acyclic graph, the intra-domain routing discovery process, the inter-domain routing discovery process, and the inter-domain routing maintenance process depends on a rapid extraction process of a shorter route in the directed acyclic graph. The invention is applicable to ad hoc network environment, can improve the reliability of the region route, can further reduce transmission delay and routing cost of the zone routing.

In accordance with exemplary embodiments of the present invention, a content addressable data structure system may include directed acyclic graphs (DAGs) of data content that are addressed using both a user-defined search key and content of data blocks. Internal keys of retention roots of the DAGs may be derived from the user-defined search key while the remaining blocks may be content addressed. As opposed to using a content address, the user may provide the search key when retrieving and deleting DAGs retaining the data content. In addition, the internal keys may be implemented using internal content addressable storage operations, such as applying a hash function and employing a distributed hash table.

Methods and systems capable of determining which subset of a set of logical expressions are true with relatively few evaluations of the primitives that, together with any standard logical connectives, make up the logical expressions. A plurality of directed acyclic graphs, each graph including at least one root node, at least one leaf node, and at least one non-leaf node associated with a leaf node. Each node is associated with a, possibly empty, subset of presumed to be true logical expressions. Each non-leaf node is associated with one of the primitives mentioned in any of the logical expressions. Edges are defined between two of the nodes, each edge being associated with a possible value, or range of possible values, of the primitive associated with the node at the tail of the edge. Paths are defined through each of the directed acyclic graphs from a root node to a leaf node by recursively following each edge corresponding to the current value of the primitive at a selected non-leaf node. Lastly, subsets of logical expressions associated with the nodes on the defined paths are collated to yield a subset of logical expressions that are true.

A system and method for assessing performance of a software application migrated to a grid infrastructure is provided. The system comprises a grid code analyzer for generating a directed acyclic graph (DAG) corresponding to the software application by performing static and dynamic analysis; a grid task generator for reducing the DAG generated by the grid code analyzer; and a grid simulator for simulating performance of the software application on one or more predetermined grid infrastructures. The grid simulator accepts the reduced DAG as input and produces performance data as output.

Each network node having at least one destination-oriented link toward a directed acyclic graph (DAG) destination can receive a corresponding set of path performance metrics via the destination-oriented link. The set of path performance metrics, initiated by the DAG destination outputting initial link metrics on each of its source-connecting links, identifies aggregate link metrics for a corresponding path to the DAG destination via the corresponding destination-oriented link. The network node outputs a corresponding updated set of path performance metrics on each of its source-connecting links based on the received set of path performance metrics and the corresponding link metric for the corresponding source-connecting link. Hence, each network node in the DAG can assess the performance of each connected path to the DAG destination, and forward a data packet via a selected destination-oriented link based on the corresponding path performance metrics and forwarding policies for the forwarded data packet.

A design verifier includes a bounded model checker, a proof partitioner and a fixed-point detector. The bounded model checker verifies a property to a depth K and either finds a counterexample, or generates a proof in the form of a directed acyclic graph. If a counterexample is found, the bounded model checker selectively increases K and verifies the property to the new larger depth using the original constraints. If no counterexample is found, the proof partitioner provides an over-approximation of the states reachable in one or more steps using a proof generated by the bounded model checker. The fixed-point detector detects whether the over-approximation is at a fixed point. If the over-approximation is at a fixed-point, the design is verified. If the over-approximation is not at a fixed point, the bounded model checker can iteratively use over-approximations as a constraint and verify the property to a depth K.

A first electronic device with a display maintains a consistent output based on concurrent textual edits received at multiple collaborating devices. The first device maintains a directed acyclic graph to represent a textual string concurrently edited by the first device and at least a second device of the multiple collaborating devices. The directed acyclic graph includes: a plurality of nodes each representing a respective character input received from one or more of the multiple collaborating devices, and multiple parallel paths each including at least one node that represents a respective one of multiple concurrent character inputs received from distinct devices of the multiple collaborating devices. The first device topologically traverses the directed acyclic graph in accordance with a predetermined ordering rule to deterministically sort the plurality of nodes into a string sequence. The first device displays the textual string in accordance with the deterministically obtained string sequence.

The invention discloses a big data job scheduling system based on a directed acyclic graph. The system comprises a database, wherein the database is used to store job tasks and all the information of service noises. The big data job scheduling system also comprises a database management module, a DAG algorithm module, a scheduling module and a monitoring module, wherein the monitoring module is connected to the scheduling module and the job tasks; the monitoring module is used to monitor information fed back by all the operated job tasks and transmit the information fed back by the job tasks to the scheduling module. The big data job scheduling system based on the directed acyclic graph provided by the invention supports task scheduling and monitoring of assemblies between big data ecologic circles, satisfies future demands for extension assemblies, can be easily equipped with two sets of management modules including a vivid management module and a standby management module, and can achieve high usability of the scheduling system.

A distributed data reorganization system and method for mapping and reducing raw data containing a plurality of data records. Embodiments of the distributed data reorganization system and method operate in a general-purpose parallel execution environment that use an arbitrary communication directed acyclic graph. The vertices of the graph accept multiple data inputs and generate multiple data inputs, and may be of different types. Embodiments of the distributed data reorganization system and method include a plurality of distributed mappers that use a mapping criteria supplied by a developer to map the plurality of data records to data buckets. The mapped data record and data bucket identifications are input for a plurality of distributed reducers. Each distributed reducer groups together data records having the same data bucket identification and then uses a merge logic supplied by the developer to reduce the grouped data records to obtain reorganized data.

A heterogeneous multi-core energy-saving task schedule method based on improved genetic algorithm comprises the improved genetic algorithm used for determining task priority and energy-saving schedule algorithm based on zooming priority. The flow of the heterogeneous multi-core energy-saving task schedule method includes (1), initializing population information; (2), entering a loop body and determining the task priority by the aid of genetic algorithm; (3), determining schedule sequence of tasks on a processor according to a task DAG (directed acyclic graph) and division strategies; (4), realizing dynamic voltage zooming on the basis of feasible task schedule according to relation of saving energy of the tasks and prolonging time; (5), calculating fitness of a current population and sorting the current population; and (6), updating the population by the aid of the improved genetic algorithm, determining new task priority, quitting if termination conditions are met, and continuing iteration if the termination conditions are not met.

A system and method for implementing a unified model for integration systems is presented. A user provides inputs to an integrated language engine for placing operator components and arc components onto a dataflow diagram. Operator components include data ports for expressing data flow, and also include meta-ports for expressing control flow. Arc components connect operator components together for data and control information to flow between the operator components. The dataflow diagram is a directed acyclic graph that expresses an application without including artificial boundaries during the application design process. Once the integrated language engine generates the dataflow diagram, the integrated language engine compiles the dataflow diagram to generated application code.

A system and a method are disclosed for transforming cluster computing resources of a target system to match a user defined logical data flow so data processing between the source and target are functionally equivalent. The source logical dataflow is compatibly mapped to a target directed acyclic graph that represents the cluster computing resources. A series of subgraph assertion and transform operations are applied iteratively until the logical data flow is isomorphic with a directed acyclic graph. The assertion and transform operations are comprised of rules and assertions, which are maintained in a rules registry.

A computer readable storage medium includes executable instructions to specify a set of database tables defining vertices and database joins defining oriented edges to form a graph. The oriented edges specify directionality characterizing dependent relationships between database tables. A query path in the graph is identified. The graph is split into a set of directed acyclic graphs. Each directed acyclic graph has a single root vertex that does not form a path to itself through oriented edges. Selected oriented edges are removed from each directed acyclic graph to form a tree corresponding to each directed acyclic graph. The tree is a sub-graph of a directed acyclic graph without loops and one list of joins relates any two database tables in the tree. A database query is generated for each tree. The database query is applied to database tables to form query results. The query results are displayed.

A method of achieving fault tolerance in a distributed stream processing system organized as a directed acyclic graph includes the initial step of managing a stream process within the distributed stream processing system including one or more operators. The one or more operators of the stream process are communicatively associated with one or more downstream operators. The method includes the steps of maintaining one or more data copies of a processing state of the one or more operators until the one or more data copies can be safely discarded, notifying the one or more operators when it is safe to discard at least one of the at least one of the one or more data copies of the processing state; and using an identifier to denote the data copy of the processing state to be safely discarded.

Decision trees are efficiently represented in a relational database. A computer-implemented method of representing a decision tree model in relational form comprises providing a directed acyclic graph comprising a plurality of nodes and a plurality of links, each link connecting a plurality of nodes, encoding a tree structure by including in each node a parent-child relationship of the node with other nodes, encoding in each node information relating to a split represented by the node, the split information including a splitting predictor and a split value, and encoding in each node a target histogram.

A method is provided for efficiently solving the matching problem in content-based publish-subscribe systems. Subscribers may define arbitrary boolean predicates as conditions to subscribe to the published event. The subscribers and their predicates can be organized in the form of a virtual Direct Acyclic Graph (DAG) such that a traversal of the DAG yields one or more matching subscribers. The present invention improves upon the conventional method of linearly matching individual subscribers against an event.