Abstract: An AC-DC converter can include: a rectifying circuit configured to convert an AC input voltage into a DC voltage, where at least one active switching device is included in one conductive rectifying loop of the rectifying circuit; a control circuit configured to control switching states of the active switching devices according to an output voltage of the AC-DC converter and the AC input voltage, in order to decrease an error between the DC voltage and the output voltage of the AC-DC converter; and a DC-DC converter configured to convert the DC voltage into the output voltage of the AC-DC converter.

Abstract: A battery charging circuit can include: a primary rectifier circuit configured to rectify an input AC voltage into a rectified voltage signal; a DC-DC converter configured to generate a charging current according to the rectified voltage signal, in order to charge a battery; a control circuit configured to adjust the charging current by controlling an operation state of the DC-DC converter according to a charging requirement, in order to make an average value of the charging current meet the charging requirement; and where the charging current is controlled to be zero when an absolute value of the input AC voltage is lower than a predetermined threshold.

Abstract: The invention discloses a mobile flash butt welding method for 136RE+SS heat-treated rail, and particularly a mobile flash butt welding method for 136RE+SS heat-treated rail in the technical field of rail welding. The mobile flash butt welding method for 136RE+SS heat-treated rail in the invention includes a pre-flash stage, a flash stage, a boost stage, an upset stage and a forge stage, with a total heat input of 7.1 MJ-10.0 MJ, a total duration of 110 s-135 s and an upsetting distance of 12.8 mm-16.7 mm during the welding process. By adopting the method of the invention, mobile flash butt welding can be conducted for 136RE+SS heat-treated rail successfully, and the rail joint has less internal defects but stable welding quality, and can pass fatigue test, tensile test and slow bend test to meet the requirements. Besides, the rail joint can pass the drop weight test for 15 welds continuously, demonstrating better stability.

Abstract: Provided is a process of modeling methods organized in racks of a machine learning pipeline to facilitate optimization of performance using modelling methods for implementation of machine learning design in an object-oriented modeling (OOM) framework, the process including: writing classes using object-oriented modelling of optimization methods, modelling methods, and modelling racks; writing parameters and hyper-parameters of the modeling methods as attributes as the modeling methods; scanning modelling racks classes to determine first class definition information; selecting a collection of rack and selecting modeling method objects; scanning modelling method classes to determine second class definition information; assigning racks and locations within the racks to modeling method objects; and invoking the class definition information to produce object manipulation functions that allow access the methods and attributes of at least some of the modeling method objects, the manipulation functions being configur

Abstract: A method uses web servers to promulgate information from one server to another, instead of promulgating the information by the user to each server individually. A first server receives a first request for promulgating web-information from a user, locally promulgates the web-information, and sends a second request to at least one second website server to instruct the second website server to locally promulgate the web-information. The selection of the second server is done according to a preset configuration file which includes a relationship mapping between the first website server and the second website server. The relationship mapping may provide the user information related to the second website server based on the user information related to the first website server. The present disclosure further discloses a communication apparatus and a communication system.

Abstract: A power converter, a control circuit and a control method for the same. Ground references of a first controller and a second controller are different to isolate drive signals of a first transistor and a second transistor. Thus the first transistor and the second transistor are controlled to be switched between on and off alternatively to achieve power conversion. The circuit is simple in structure and easy to implement with a low cost. The ground reference of the first controller is an intermediate node of a bridge arm of the power converter, so as to facilitate sampling and acquiring a feedback signal, thereby achieving closed-loop control of the power converter.

Abstract: An AC-DC conversion circuit can include an adaptive rectifier configured to receive an AC input voltage with different ranges, where operation states of the adaptive rectifier are adjusted according to a range of the AC input voltage, in order to decrease a fluctuation range of a DC output voltage of the adaptive rectifier.

Abstract: A primary feedback control circuit of a series resonant converter having a transformer, can include: an excitation current simulation circuit configured to sample an excitation voltage of the transformer, and to generate a first voltage representing an excitation current of the transformer; and a feedback control circuit configured to control on and off states of power switches of the series resonant converter in accordance with the first voltage and a second voltage representing a resonant current of the series resonant converter, where the first voltage is controlled to be equal to the second voltage when a secondary current of the transformer is zero.

Abstract: The present disclosure discloses a method and apparatus for rendering a navigation image and storage medium, the method including: changing a frame limiting parameter according to a current navigation state parameter; and performing frame limiting processing on navigation image rendition according to the frame limiting parameter. According to the embodiments of the present disclosure, a rendered navigation image is determined according to the frame limiting parameter of the current navigation based on the navigation state parameters obtained by a mobile terminal, and the power consumption of the mobile terminal can be reduced without affecting the navigation map and the animated display effect, thereby increasing the per charge usage of the mobile terminal and enhancing the user experience.

Abstract: A gesture position correcting method includes obtaining position information of a gesture performed by a gesture-performing object, calculating a position deviation of the gesture according to a distance and an angle between a depth camera capturing the gesture and a user eye, and correcting the position information according to the position deviation.

Abstract: An AC-DC power converter can include: a front-stage power circuit; a rear-stage power circuit configured to share one power switch as a main power switch with the front-stage power circuit, where the rear-stage power circuit is coupled to a load, and a first magnetic component of the front-stage power circuit and a second magnetic component of the rear-stage power circuit are not coupled in one conductive loop from a positive terminal of a DC input voltage to a negative terminal of the DC input voltage; and an energy storage capacitor coupled to the front-stage power circuit and the rear-stage power circuit, where a common node of the first and second magnetic components is directly coupled to the power switch.

Abstract: An AC-DC power converter can include: a front-stage power circuit; a rear-stage power circuit configured to share one power switch as a main power switch with the front-stage power circuit, where the rear-stage power circuit is coupled to a load, and a first magnetic component of the front-stage power circuit and a second magnetic component of the rear-stage power circuit are not in one conductive loop from a positive terminal of a DC input voltage to a negative terminal of the DC input voltage; and an energy storage capacitor coupled to the front-stage power circuit and the rear-stage power circuit, where energy is transferred to the energy storage capacitor and the load when the first magnetic component is discharged.

Abstract: A power converter, a control circuit and a control method for the same. Ground references of a first controller and a second controller are different to isolate drive signals of a first transistor and a second transistor. Thus the first transistor and the second transistor are controlled to be switched between on and off alternatively to achieve power conversion. The circuit is simple in structure and easy to implement with a low cost. The ground reference of the first controller is an intermediate node of a bridge arm of the power converter, so as to facilitate sampling and acquiring a feedback signal, thereby achieving closed-loop control of the power converter.

Abstract: A ripple suppression circuit configured to suppress a current ripple provided to a load by a DC converter, can include: a ripple voltage sampling circuit coupled to output terminals of the DC converter, where the ripple voltage sampling circuit is configured to generate a ripple reference voltage that represents a ripple voltage of an output voltage of the DC converter; and a voltage regulation circuit coupled to the load and the ripple voltage sampling circuit, where the voltage regulation circuit is controllable by the ripple reference voltage such that a voltage across the voltage regulation circuit is consistent with the ripple voltage.

Abstract: A method for managing projection of an electronic device includes obtaining ambient parameters of a projection screen, and adjusting a size or brightness level of a projection image projected on the projection screen by the electronic device, based on the ambient parameters. The present disclosure also provides an electronic device and a projector.

Abstract: A ripple suppression circuit for suppressing a ripple component in a drive current for an LED load includes: an output port connected to the LED load; a current filter circuit connected in series with the output port, and being configured to control the drive current based on an output voltage after a ripple component is filtered out, where the drive current is maintained as substantially stable; and a ripple shunt circuit connected between a drive current input terminal and a ground terminal, and being configured to shunt the drive current in response to the output voltage, where the output voltage is a voltage output from a power stage circuit that is coupled to the ripple suppression circuit.

Abstract: The invention discloses a mobile flash butt welding method for 136RE+SS heat-treated rail, and particularly a mobile flash butt welding method for 136RE+SS heat-treated rail in the technical field of rail welding. The mobile flash butt welding method for 136RE+SS heat-treated rail in the invention includes a pre-flash stage, a flash stage, a boost stage, an upset stage and a forge stage, with a total heat input of 7.1 MJ-10.0 MJ, a total duration of 110 s-135 s and an upsetting distance of 12.8 mm-16.7 mm during the welding process. By adopting the method of the invention, mobile flash butt welding can be conducted for 136RE+SS heat-treated rail successfully, and the rail joint has less internal defects but stable welding quality, and can pass fatigue test, tensile test and slow bend test to meet the requirements. Besides, the rail joint can pass the drop weight test for 15 welds continuously, demonstrating better stability.

Abstract: The present disclosure provides a method for implementation of wireless relaying. The method is applied to a wireless relay device. The method comprises: a wireless relay device sends a probe request packet carrying a first detection code and device information of the wireless relay device; receive a probe response packet sent by a first wireless routing device, the probe response packet carrying an SSID and a password corresponding to the first wireless routing device; and send an authentication request packet to a second wireless routing device, the authentication request packet carrying the SSID and the password that is carried in the probe response packet sent by the second wireless routing device to the wireless relay device, and the second wireless routing device being one of the first wireless routing devices.

Abstract: A method and apparatus for displaying road names and a storage medium, the method comprises: performing collision detecting on and loading planned road names according to planned road name data and priority levels of the planned road names included in a navigation route; and performing collision detecting on and loading annotations of other map contents except the navigation route in a navigation map. The method and apparatus for displaying road names and the storage medium are used to enable a user to view the planned road names of the navigation route on an overview page of the navigational route, thereby improving guidance of map display for navigation.

Abstract: A method, apparatus and storage medium for controlling a navigation map. The method includes: acquiring navigation key points contained in a navigation route between a current position of a vehicle and a next maneuver point, upon detecting a scale display event; calculating an optimal scale of the navigation map, according to the navigation key points and a pixel size of a terminal screen; and navigating the navigation route according to the optimal scale. The method, apparatus and storage medium for controlling a navigation map provided by the embodiments of the present disclosure improve the guidance of the navigation map and reduce the risk of missing an intersection during driving.