Abstract: A direct drive motor includes a base, a stator assembly provided on the outer periphery of the base, a rotating shaft assembly provided in the base, and a rotor assembly connected to the rotating shaft assembly and covering the stator assembly. The base includes an inner end, an outer end, and a receiving chamber passing through the inner end and the outer end. The rotating shaft assembly is rotatably mounted in the receiving chamber. A first circuit board is mounted at the inner end; a recess is formed in the outer end; a second circuit board is mounted in the recess; and the first circuit board is connected to the second circuit board. When being applied to an apparatus such as an intelligent device and an intelligent robot, the direct drive motor is good in stability, high in intelligence, reliable in overall structure, and strong in practicability.

Abstract: A light-emitting device includes a semiconductor epitaxial structure including a first semiconductor layer, an active layer, and a second semiconductor layer, and having holes; a first insulation layer disposed on the semiconductor epitaxial structure and having first and second grooves; a first pad electrically connected to the first semiconductor layer through the first grooves; and a second pad electrically connected to the second semiconductor layer through the second grooves. A projection of the first pad does not overlap projections of the holes. A projection of the second pad does not overlap the projections of the holes. The first pad includes a first pad connection portion and first pad extension portions; the second pad includes a second pad connection portion and second pad extension portions. Projections of the second grooves fall between projections of the first and second pad extension portions. Two other aspects of the light-emitting device are also provided.

Abstract: Computer-readable media, methods, and systems are disclosed for utilizing partition-based locking mechanisms to improve execution of overlapping data definition language (DDL) and data manipulation language (DML) operations on a partitioned database table. A first node receives a DML statement associated with a first transaction. The first node acquires a intent exclusive lock on table metadata. A second node receives a DDL statement associated with a second transaction and acquires an exclusive metadata lock on the partitioned table metadata. Next, an intent exclusive lock is acquired for the relevant partition table data on the second node and an exclusive lock on table metadata on the second node. The second transaction waits for the DML operation of the first transaction to complete. Then the first transaction is committed. Finally exclusive locks are acquired on table data and metadata and the second transaction is executed and committed.

Abstract: Computer-readable media, methods, and systems are disclosed for database table partition pruning based on statistical information associated with non-partition columns. A tree partition specification is received defining partitions for a plurality of computed column statistics. Respective partitions are created for the plurality of computed column statistics based on the tree partition specification. A request is received to compute statistics for a plurality of columns of the plurality of computed column statistics to result in a plurality of computed column statistics. In response to determining that one or more modifications have been made to the partitioned database, the plurality of computed column statistics is marked as invalid. The computed column statistics are refreshed in response to modifications of the partitioned table. Thereafter, the statistics are marked as valid. Unnecessary table partitions are pruned based on the statistics, and the associated query is executed.

Abstract: A collision avoidance method for an autonomous driving vehicle (ADV), the method comprising: A) obtaining a current vehicle state of the ADV and a planned trajectory of the ADV over a predetermined drive period, wherein the planned trajectory is generated according to an initial vehicle state of the ADV and an environment of the ADV when the ADV is at the initial vehicle state, and wherein the initial vehicle state is a vehicle state of the ADV when the ADV is at a start point of the predetermined drive period; B) generating a simulated trajectory over at least a portion of the predetermined drive period based on the current vehicle state and the planned trajectory; C) determining whether the simulated trajectory overlaps with an obstacle; and D) decelerating the ADV in response to a determination result that the simulated trajectory overlaps with an obstacle.

Abstract: A method for controlling a vehicle using a model predictive controller generating consecutive sets of reference states at a calculation frequency. In one embodiment, the method comprises: receiving a trajectory reference for guiding movement of the vehicle; generating, in a calculation cycle repeated at the calculation frequency, a set of reference states based on an initial state of the vehicle at a start time of the calculation cycle and the trajectory reference; sending the set of reference states to a second controller; detecting, by the second controller at a detection frequency equal to or higher than the calculation frequency, an updated state of the vehicle; generating a vehicle control parameter value based on the updated state of the vehicle and a reference state of the set of reference states; and controlling the vehicle using the vehicle control parameter value.