Abstract: An approach is provided for optimizing a join operation that includes receiving, by one or more processors of a computer system, a join request associated with a fact table and a plurality of related dimension tables; identifying, by the one or more processors of the computer system, a join relationship from the fact table and the plurality of related dimension tables; matching, by the one or more processors of the computer system, different tables of the fact table and the plurality of related dimension tables; filtering, by the one or more processors of the computer system using data parallelism, the fact table and the plurality of related dimension tables, wherein the filtering occurs prior to performing the join request; and performing, by the one or more processors of the computer system, the join operation pursuant to the join request.

Abstract: Disclosed embodiments provide a computer-implemented technique for creating a log chain from multiple software component logs. The log chain can include log information from multiple software components that interact with each other. In embodiments, a locality-sensitive hashing technique is used to create a signature of a log chain. Machine-learning systems are trained with log chains generated from test execution, and/or log chains from incidents with deployed software. In embodiments, logs are pre-processed by tokenizing and trimming. Logs from various components that interact with each other may be combined into a temporally sequential log chain. The signature of the log chain may be used to identify additional information about the error from a machine-learning process that was trained on previously generated log chains. In this way, the time required to identify a problem can be significantly reduced, resulting in increased reliability and availability of complex computer systems.

Abstract: A data-replication system replicates a source database to a target database by first intelligently identifying and prioritizing a set of hot queries that have each in the past been submitted to the source database at a rate exceeding a threshold submission rate. Any previously replicated content contained in a database table accessed by a hot query is copied to a set of memory-resident blocks. The blocks are then updated with incremental changes made to the table's contents since the most-recent previous replication. Each updated block is copied to the target database in order of the priority of the block's corresponding hot query. When all blocks that contain data of a particular table have been copied into the target database, that table becomes available to users of the target database despite the fact that the entire database has not yet been fully replicated.

Abstract: A low-speed signal conversion module for a DP interface is provided, including a protocol parsing module, an encoding module, a decoding module, a sending link, and a receiving link. The protocol parsing module is configured to parse a DP protocol, and send a low-speed signal of the DP interface to the encoding module, or send an output signal of the decoding module to the DP interface. The encoding module is configured to perform encoding in different forms respectively according to different outputs of the protocol parsing module, and transmit the encoded signal to the sending link. In the present invention, different combinations of combined AUX, HPD and null signals are line-encoded respectively according to characteristics of a DP protocol.

Abstract: An approach is provided for accessing data in a database. A query which accesses item(s) in the data is received. The query has multiple conditions whose execution produces a final result. Amounts of filtering of portions of the data caused by utilizing different types of indexes to filter the portions are determined. Greatest amounts of filtering for the portions are determined. Types of indexes are selected so that a utilization of a given type of index causes a greatest amount of filtering for a given portion. Data access methods for the portions of data are generated. During runtime, process tasks are generated for the multiple conditions in the query. An execution flow is controlled. The execution flow executes the process tasks by utilizing the data access methods to generate initial results. The final result of the query is generated by combining the initial results from the process tasks.

Abstract: This disclosure provides a computer-implemented method. The method may comprise obtaining a character of first-direction communications and a character of second-direction communications in a network environment, the first-direction communications being network communications from a first node to a second node, and the second-direction communications being network communications from the second node to the first node. The method may further comprise determining a dependency between the first node and the second node based on the character of first-direction communications and the character of second-direction communications, the dependency between the first node and the second node indicating whether the first node depends on the second node or the second node depends on the first node.

Abstract: Methods and systems for reducing database maintenance effort are disclosed. A method includes: collecting, by a computing device, a history of statistics for database objects; predicting, by the computing device, statistics using the history of statistics; testing, by the computing device, a workload using the predicted statistics; determining, by the computing device, at least one database object to maintain based on the testing the workload; and maintaining, by the computing device, the determined at least one database object.

Abstract: A symmetric method for obtaining bus-translation-voltage components induced by sources and loads at individual buses in AC power networks is invented. Two linear expressions of bus injection active and reactive powers in terms of translation voltages and voltage angles of all buses are established according to branch admittances and bus injection powers of sources and loads. Then a linear symmetric matrix-equation model for the steady state of the network is built. Manipulating this model by Moore-Penrose pseudoinverse produces a linear symmetric matrix expression of translation voltages and voltage angles of all buses in terms of bus injection powers. Finally a linear symmetric algebraic calculation formula for obtaining the bus-translation-voltage components is extracted from this matrix expression to achieve obtaining of the bus-translation-voltage components.

Abstract: A linear asymmetric method for examining branch-outage-type steady-state security of AC power networks is provided. Two linear expressions of bus injection active and reactive powers in terms of translation voltages and voltage angles of all buses are established. Then a linear asymmetric matrix-equation model for the steady state of the network is built considering the reference bus number. Manipulating this model produces the matrix expression of branch-not-outage-type translation voltages and voltage angles of non-reference buses and the bus impedance matrix with the reference bus discarded. The branch-outage-type translation-voltage increments and voltage-angle increments of non-reference buses are then obtained by the bus impedance matrix and the outage branch using the calculation formula of ordinary inverse of a modified matrix. The examination of the steady-state security of the network is achieved using these increments.

Abstract: A symmetric method for obtaining network-power-loss components induced by sources and loads at individual buses in AC power networks is invented. Two linear expressions of bus injection active and reactive powers in terms of translation voltages and voltage angles of all buses are established at first. Then a linear symmetric matrix-equation model for the steady state of the network is built. Manipulating this model by Moore-Penrose pseudoinverse produces a linear symmetric matrix expression of translation voltages and voltage angles of all buses in terms of bus injection powers. Expressing the network power loss in terms of source's and load's powers by this matrix expression, a symmetric algebraic calculation formula for obtaining the network-power-loss components is produced after manipulating by Shapley value theorem, by which the obtaining of network-power-loss components are achieved. The set of network-power-loss components provides a new efficient tool for economic operation of AC power networks.

Abstract: Data segment-based indexing includes identifying data segments of a column of a database based on a data distribution of data of the column, indexing the data segments, including, for each data segment, determining an index type and creating an index of the determined index type, and building a composite link between indexes of a common index type, which indexes of the common index type include a created index, from indexing the data segments of the column, of the common index type and at least one other index, of the common index type, which is for other data segment(s), of other column(s) of the database, that have been indexed using the common index type. The composite link provides for parallel searching against the indexes in the group to search corresponding different data segments, in different columns of the database, indexed using the common index type.

Abstract: Disclosed embodiments provide techniques for database query utilizing a multigram index. In embodiments, a search query is divided into multiple regex subcomponents. Regex subcomponent indexes are created and searched in parallel, and/or in a sequential manner on reduced data sets, increasing search performance, especially for NoSQL databases.

Abstract: According to some embodiments, a system receives a first control command and a speed measurement of the ADV. The system determines an expected acceleration of the ADV based on the speed measurement and the first control command. The system receives an acceleration measurement of the ADV. The system determines a feedback error based on the acceleration measurement and the expected acceleration. The system updates a portion of the calibration table based on the determined feedback error. The system generates a second control command to control the ADV based on the calibration table having the updated portion to control the ADV autonomously according to the second control command.

Abstract: In one embodiment, a lateral drifting error is determined based on at least a current location of an ADV. The lateral drifting error is segmented into a first drifting error and a second drifting error using a predetermined segmentation algorithm. A planning module plans a path or trajectory for a current driving cycle (e.g., planning cycle) to drive the ADV from the current location for a predetermined period of time. The planning module performs a first drifting error correction on the trajectory by modifying at least a starting point of the trajectory based on the first drifting error to generate a modified trajectory. A control module controls the ADV to drive according to the modified trajectory, including performing a second drifting error correction based on the second drifting error.

Abstract: A first localization system performs a first localization using a first set of sensors to track locations of the ADV along the path from a starting point to a destination point. A first localization curve is generated as a result representing the locations of the ADV along the path tracked by the first localization system. Currently, a second localization system performs a second localization using a second set of sensors to track the locations of the ADV along the path. A second localization curve is generated as a result representing the locations of the ADV along the path tracked by the second localization system. A system delay of the second localization system is determined by comparing the second localization curve against the first localization curve as a localization reference. The system delay of the second localization system can then be utilized to compensate path planning of the ADV subsequently.

Abstract: Provided are an adaptor element in a bubble shape, a method of constructing a sequencing library with such an adapter element. The adaptor element is a hybrid formed with a long-chain nucleic acid A and a short-chain nucleic acid B. The hybrid is in the bubble shape with paired regions at two terminals and a non-paired region in the middle.

Abstract: In one embodiment, instead of using map data, a relative coordinate system is utilized to assist perception of the driving environment surrounding an ADV for some driving situations. One of such driving situations is driving on a highway. Typically, a highway has fewer intersections and exits. The relative coordinate system is utilized based on the relative lane configuration and relative obstacle information to control the ADV to simply follow the lane and avoid potential collision with any obstacles discovered within the road, without having to use map data. Once the relative lane configuration and obstacle information have been determined, regular path and speed planning and optimization can be performed to generate a trajectory to drive the ADV. Such a perception system is referred to as a relative perception system based on a relative coordinate system.

Abstract: In an approach to seamlessly migrating data and index in distributed database systems, when a data migration request is received, a source data and a source index are migrated from a source cluster to a target cluster. When new data is received from a client to be written to the source data during the data migration, a delta data and a delta index are stored to a portable data storage, where the delta data is the new data from the client, and the delta index is created from the delta data. When the data migration from the source cluster to the target cluster is complete, the delta data and the delta index are migrated from the portable data storage to the target cluster.

Abstract: A low-speed signal conversion module for a DP interface is provided, including a protocol parsing module, an encoding module, a decoding module, a sending link, and a receiving link. The protocol parsing module is configured to parse a DP protocol, and send a low-speed signal of the DP interface to the encoding module, or send an output signal of the decoding module to the DP interface. The encoding module is configured to perform encoding in different forms respectively according to different outputs of the protocol parsing module, and transmit the encoded signal to the sending link. In the present invention, different combinations of combined AUX, HPD and null signals are line-encoded respectively according to characteristics of a DP protocol.

Abstract: A method, system, and program product for modifying a high performance multi-write database is provided. The method includes registering data pages configured for reading by a first node within a buffer pool structure of a database. Share lock functionality is enabled. The share lock functionality is disabled after the first node has completed reading the data pages and the data pages are registered with respect to a second node for writing functionality. A notification indicating that a group of data pages has expired is generated and transmitted to the second node. Exclusive lock functionality for allowing the second node to read and modify the data pages is enabled and after the modification the exclusive lock functionality is disabled. Reading functionality is enabled for the first and second nodes to read the group of data pages from a high performance cache structure of the buffer pool structure.