Abstract: The disclosure provides a method, an electronic device, and a storage medium for training a federated learning model. According to the method, the electronic device, and the storage medium for training a federated learning model provided in the disclosure, after each of participant devices obtains gradient information of the participant device by performing joint encryption training with a rest of the participant devices, the participant device performs joint training with the rest of the participant devices based on a model parameter variation and a gradient information variation, to obtain a corresponding gradient search direction; then a target participant device of the participant device calculates step information based on the gradient search direction and a model loss function; finally, each of the participant devices updates a model parameter of the participant device based on the gradient search direction and the step information.

Abstract: A folding wave-energy-harvesting mechanism for an underwater vehicle includes an underwater-vehicle main body and a wave-energy-harvesting-device main body. The wave-energy-harvesting-device main body includes a hydrofoil assembly and a yaw assembly. The first state of the hydrofoil assembly is a folding state, and the second state is an unfolding state. The first state of the yaw assembly is the folding state, and the second state is the unfolding state. The wave-energy-harvesting-device main body further includes a driving assembly and an energy-storage assembly. The driving assembly is configured to switch the hydrofoil assembly and the yaw assembly in the first state and the second state to each other. The energy-storage assembly is configured to store the wave energy harvested by the hydrofoil assembly. When the hydrofoil assembly and the yaw assembly unfold, the hydrofoil assembly increases the efficient area for wave-energy harvesting.

Abstract: In accordance with an embodiment, a data processing method includes: obtaining a first operation command, where the first operation command is used to perform data processing in a relational database; determining an acceleration policy of the first operation command, wherein the acceleration policy is used to accelerate a processing process of the first operation command; and performing an operation of the first operation command based on the acceleration policy.

Abstract: A database management method and apparatus are provided. The database management method includes: obtaining statistical data of first database resources in a database, where the statistical data is usage data of the first database resources that is obtained through statistical collection; extracting a first usage feature of the first database resources from the statistical data; inputting the first usage feature into a competition evaluation model, to obtain an evaluation result, where the competition evaluation model is obtained through training based on a second usage feature of at least one database resource; and outputting competition alarm information when the evaluation result indicates that a second database resource is an abnormal resource, where the competition alarm information indicates that a competitive bottleneck occurs in the second database resource, and the second database resource is some or all of the first database resources.

Abstract: A folding wave-energy-harvesting mechanism for an underwater vehicle includes an underwater-vehicle main body and a wave-energy-harvesting-device main body. The wave-energy-harvesting-device main body includes a hydrofoil assembly and a yaw assembly. The first state of the hydrofoil assembly is a folding state, and the second state is an unfolding state. The first state of the yaw assembly is the folding state, and the second state is the unfolding state. The wave-energy-harvesting-device main body further includes a driving assembly and an energy-storage assembly. The driving assembly is configured to switch the hydrofoil assembly and the yaw assembly in the first state and the second state to each other. The energy-storage assembly is configured to store the wave energy harvested by the hydrofoil assembly. When the hydrofoil assembly and the yaw assembly unfold, the hydrofoil assembly increases the efficient area for wave-energy harvesting.

Abstract: The present invention provides method and apparatus for power management of mobile devices and associated mobile devices. The method for power management of mobile devices includes acquiring a predefined battery power level variation ?n of the mobile device and its corresponding usage time t1 if the mobile device uses the power-saving functions; acquiring the same battery power level variation ?n of the mobile device and its corresponding usage time t2 if the mobile device does not use any power-saving function; and determining an extended usage time of the mobile device ?t=t1?t2, and notifying the user of the mobile device the extended usage time. By determining the extended usage time and notifying the user of the extended usage time, the user of the mobile device can have a better understanding of the usage state of the mobile device after adopting the power-saving functions and therefore an improved user experience.

Abstract: A method, an apparatus and a mobile device estimate remaining time required to fully charge a battery. The method may include (a) determining from one or more of the mobile device's charging records the time required for charging the battery of the mobile device by one unit of charge (“unit charging time”); and (b) based on the time so determined, calculating the remaining time required for fully charging the mobile device's battery. In this manner, an accurate estimate of the remaining charging time is achieved. In one instance, the charging record includes the initial charge (A) in the battery, expressed as a percentage of the full capacity, the final charge (B) in the battery at the end of the charging, also expressed as a percentage of full capacity, and the total charging time required (T). Each unit of charge may be, for example, 1% of the full charge of the battery.

Abstract: The present invention provides method and apparatus for power management of mobile devices and associated mobile devices. The method for power management of mobile devices includes acquiring a predefined battery power level variation ?n of the mobile device and its corresponding usage time t1 if the mobile device uses the power-saving functions; acquiring the same battery power level variation ?n of the mobile device and its corresponding usage time t2 if the mobile device does not use any power-saving function; and determining an extended usage time of the mobile device ?t=t1?t2, and notifying the user of the mobile device the extended usage time. By determining the extended usage time and notifying the user of the extended usage time, the user of the mobile device can have a better understanding of the usage state of the mobile device after adopting the power-saving functions and therefore an improved user experience.