Abstract: The disclosed technologies are capable of selectively using data structure operations for path query evaluation. One technique involves reading a query that traverses at least two nodes and at least one edge of a graph in a graph database; compiling the query into a set of variables and a set of constraints, where the set of variables and the set of constraints correspond to the two nodes and the one edge of the graph; creating an in-memory data structure that comprises a table; using the set of variables and the set of constraints to determine an operation that is performable using the in-memory data structure; checking for an existence of a condition relating to the in-memory data structure or the operation; skipping the operation if the condition exists or executing the operation if the condition does not exist; and storing a set of intermediate query results in the table.

Abstract: The disclosed technologies are capable of decentralized query evaluation for a distributed graph database. In one technique, a query is divided into first and second sets of operations. The query comprises variables and constraints that correspond to at least two nodes and at least one edge of a graph in a graph database. The first set of operations for processing the query is assigned to multiple shards. A limit is communicated to the shards. The second set of operations for processing the query is executed. A list of completed operations is received from each shard. The lists of operations received from the shards are merged into a merged set of operations, which is used to determine whether query processing is finished. If query processing is not finished, then an updated limit is communicated to the shards; otherwise, query results are provided in response to the query.

Abstract: The disclosed technologies are capable of selectively using data structure operations for path query evaluation. One technique involves reading a query that traverses at least two nodes and at least one edge of a graph in a graph database; compiling the query into a set of variables and a set of constraints, where the set of variables and the set of constraints correspond to the two nodes and the one edge of the graph; creating an in-memory data structure that comprises a table; using the set of variables and the set of constraints to determine an operation that is performable using the in-memory data structure; checking for an existence of a condition relating to the in-memory data structure or the operation; skipping the operation if the condition exists or executing the operation if the condition does not exist; and storing a set of intermediate query results in the table.

Abstract: The present invention discloses methods and systems for detecting the health status of a bolt which fastens a rotor blade of a wind turbine. Values of the axial stress/strain of the bolt and motion and orientation data are acquired in different aerial orientations. Values of the prestress/strain and load-stress/strain are obtained using the values of the axial stress/strain and the motion and orientation data. Values of the prestress/strain and load-stress/strain are compared with the reference values. The health status of the bolt, rotor blade, and the wind turbine system is determined based on the comparison results. The method is noninvasive and doesn't affect the function and performance of the bolt and the turbine system.

Abstract: The present invention discloses methods and systems for detecting the health status of a bolt which fastens a rotor blade of a wind turbine. Values of the axial stress/strain of the bolt and motion and orientation data are acquired in different aerial orientations. Values of the prestress/strain and load-stress/strain are obtained using the values of the axial stress/strain and the motion and orientation data. Values of the prestress/strain and load-stress/strain are compared with the reference values. The health status of the bolt, rotor blade, and the wind turbine system is determined based on the comparison results. The method is noninvasive and doesn't affect the function and performance of the bolt and the turbine system.

Abstract: The disclosed embodiments provide a system for managing code and data in a multi-cluster environment. During operation, storage nodes in a first cluster execute instances of a scheduler that initiates actions including creating a database image, copying the database image, and loading the database image. Next, the scheduler issues, to a synchronization service, a first action to be performed by a second cluster based on a deployment schedule for data in a distributed database. Upon receiving a confirmation that the first action has been completed, the first cluster performs a second action received from the synchronization service to manage deployment of data in the distributed database on the first cluster. Upon completing the second action at a storage node in the first cluster, the storage node issues a completion of the second action to the synchronization service.