Abstract: An operation prediction method includes obtaining a first embedding representation and a second embedding representation of attribute information of a user and an item respectively by using a first feature extraction network and a second feature extraction network. The first embedding representation indicates a feature unrelated to recommendation scenario information. The second embedding representation indicates a feature related to a target recommendation scenario. The first embedding representation and the second embedding representation are used for fusion to obtain a fused embedding representation. The operation prediction method further includes predicting target operation information of the user for the item based on the fused embedding representation.

Abstract: A multi-level conversion circuit and a cycle-by-cycle protection method therefor are provided. The cycle-by-cycle protection method includes steps of: (a) determining main switches and synchronous rectification switches; (b) controlling the main switches to operate in a normal mode; (c) detecting a current flowing through the inductor, and determining whether the current exceeds a threshold; (d) when the current exceeds the threshold, defining the main switch in an on state and having longest turn-on duration as a target main switch, switching the target main switch to a current limiting mode; and (e) after the target main switch is switched to the current limiting mode, if the current is lower than the threshold, at a moment when a rising edge of a control signal in a reference mode for the target main switch firstly appears, switching the target main switch to a state in the reference mode corresponding to the moment.

Abstract: A multi-level conversion circuit and a cycle-by-cycle protection method therefor are provided. The cycle-by-cycle protection method includes steps of: (a) determining main switches and synchronous rectification switches; (b) controlling the main switches to operate in a normal mode; (c) detecting a current flowing through the inductor, and determining whether the current exceeds a threshold; (d) when the current exceeds the threshold, defining the main switch in an on state and having shortest turn-on duration as a target main switch, switching the target main switch to a current limiting mode for turning it off; and (e) after switching the target main switch to the current limiting mode, if the current is lower than the threshold, at a moment when a falling edge of control signals in a reference mode for the main switches first appears, switching the target main switch to a state in the reference mode corresponding to the moment.

Abstract: A multi-level conversion circuit and a cycle-by-cycle protection method therefor are provided. The cycle-by-cycle protection method includes steps of: (a) determining main switches and synchronous rectification switches; (b) controlling the main switches to operate in a normal mode; (c) detecting a current flowing through the inductor, and determining whether the current exceeds a threshold; (d) when the current exceeds the threshold, defining the main switch in an on state as a target main switch, switching the target main switch to a current limiting mode for turning off the target main switch; and (e) after the target main switch is switched to the current limiting mode, if the current is lower than the threshold, at a moment when a falling edge of control signals in a reference mode for the main switches first appears, switching the target main switch to a state in the reference mode corresponding to the moment.

Abstract: A non-road engine is provided. The non-road engine includes a carburetor and a combination switch for controlling on-off of a fuel supply pipe between a fuel tank and the carburetor, where the carburetor is provided with a control valve for controlling opening and closing of a main jet; the control valve is linked and matched with the combination switch; when the combination switch is in an on state, the control valve causes the main jet to be in an open state; and when the combination switch is in an off state, the control valve causes the main jet to be in a closed state.

Abstract: The application provides a power supply device comprising two input ports disposed at a front end of the power supply device; at least one fan disposed behind the two input ports and two isolated power supplies connected respectively to the corresponding one of the two input ports and disposed behind the two input ports and the at least one fan. Each of the isolated power supplies comprises a main power circuit having at least one module, and each module comprises a PCB and a magnetic element and/or switching devices. The at least one module includes an isolated circuit module comprises a transformer having windings formed by laying copper in the PCB and the magnetic core fixed on the PCB. And at least one fan is configured for heat dissipation of the at least one module.

Abstract: Multilevel conversion circuit having a flying capacitor and method for pre-charging the same are provided. The multilevel conversion circuit includes: a first bridge arm including a plurality of switches connected in series; a second bridge arm including a plurality of switches connected in series and a flying capacitor group, midpoints of the two bridge arms connected to a power supply and an inductor to form a series branch; a DC bus capacitor to which the two bridge arms are connected in parallel; a first voltage clamping module connected between a first end of the flying capacitor group and a first end of the DC bus capacitor; and a second voltage clamping module connected between a second end of the flying capacitor group and a second end of the DC bus capacitor.

Abstract: This application discloses an information recommendation method, which may be applied to the field of artificial intelligence. The method includes: obtaining a target feature vector; and processing the target feature vector by using a recommendation model, to obtain recommendation information, where the recommendation model includes a cross network, a deep network, and a target network; the target network is used to perform fusion processing on a first intermediate output that is output by the first cross layer and a second intermediate output that is output by the first deep layer, to obtain a first fusion result, and the target network is further used to: process the first fusion result to obtain a first weight corresponding to the first cross layer and a second weight corresponding to the first deep layer, and weight the first fusion result with the first weight and the second weight separately.

Abstract: A multi-level conversion circuit and a control method for flying capacitor voltage thereof are provided. In the multi-level conversion circuit, each flying capacitor is connected between a common connection node of the lower switches connected therewith and a common connection node of the upper switches connected therewith. The control method includes steps of: (a) determining the main switch and synchronous rectification switch of the lower and upper switches; (b) acquiring an adjustment value corresponding to each flying capacitor; (c) adjusting a duty ratio of the main switch according to the adjustment value corresponding to the flying capacitor connected therewith; and (d) when the multi-level conversion circuit working in a CCM, increasing a phase-shift angle between the main switches by an angle to make a peak value or a valley value of an inductor current remain unchanged before and after adjusting the duty ratio.

Abstract: In the present disclosure, the multi-level AC/DC conversion circuit and the multi-level DC/DC conversion circuit calculate the duty ratio of synchronous rectification switch according to the input voltage, the output voltage, the interval time of turning on the main switch, the switching cycle and the duty ratio of main switch, thereby eliminating the need for additional zero-current detecting function or zero-crossing detection circuit in conventional AC/DC conversion circuits. Accordingly, for the multi-level AC/DC conversion circuit and the multi-level DC/DC conversion circuit of the present disclosure, the cost is reduced, and the reliability is enhanced.

Abstract: A multi-level conversion circuit and a control method for flying capacitor voltage thereof are provided. In the multi-level conversion circuit, each flying capacitor is connected between a common connection node of the lower switches connected therewith and a common connection node of the upper switches connected therewith. When the conversion circuit works in a DCM, the control method includes steps of: (a) determining the main switch and synchronous rectification switch of the lower and upper switches; (b) acquiring an adjustment value corresponding to each flying capacitor; and (c) adjusting a duty ratio of the main switch according to the adjustment value corresponding to the flying capacitor connected therewith, wherein the adjustment trend of the duty ratio under D<(N?2)/(N?1) is opposite to that under (N?2)/(N?1)<D?1, and D is the duty ratio before the adjustment.

Abstract: A non-road mobile machinery (NRMM) is provided and includes a fuel storage device, a fuel supply device, a vapor adsorption device, and an engine body. The vapor adsorption device is provided with an air vent communicated to the atmosphere. A vapor discharge hole of the fuel storage device is communicated to an adsorption vent of the vapor adsorption device. The NRMM also includes a valve mechanism connected between a desorption vent of the vapor adsorption device and an intake channel of the engine body. The valve mechanism is conducted with the working of the engine body and blocked with the stop of the engine body. The NRMN improves the evaporation emission performance of the NRMM when compared to the prior art and solves the problem that the evaporation emissions of the NRMM in the prior art are prone to exceed the standard.

Abstract: A multilevel conversion circuit having a flying capacitor is provided, including: a first bridge arm; a second bridge arm including a flying capacitor, the midpoints of the second and first bridge arms connected to a series branch defined by a first current limiting circuit, a power supply and an inductor; a DC bus capacitor connected in parallel to the first and second bridge arms; a rectifier circuit having an input end coupled to the power supply and an output end connected to a first auxiliary power supply; and a controller coupled to the first auxiliary power supply and the plurality of switches of the second bridge arm to control corresponding switches of the second bridge arm, the power supply charges the flying capacitor through the corresponding switches of the first and second bridge arms and the first current limiting circuit.

Abstract: Multilevel conversion circuit having a flying capacitor and method for precharging the same are provided. The multilevel conversion circuit includes: a first bridge arm including a plurality of switches connected in series; a second bridge arm including a plurality of switches connected in series and a flying capacitor group, midpoints of the two bridge arms connected to a power supply and an inductor to form a series branch; a DC bus capacitor to which the two bridge arms are connected in parallel; a first voltage clamping module connected between a first end of the flying capacitor group and a first end of the DC bus capacitor; and a second voltage clamping module connected between a second end of the flying capacitor group and a second end of the DC bus capacitor.

Abstract: A multilevel conversion circuit having a flying capacitor is provided, including: a first bridge arm; a second bridge arm including a flying capacitor, the midpoints of the second and first bridge arms connected to a series branch defined by a first current limiting circuit, a power supply and an inductor; a DC bus capacitor connected in parallel to the first and second bridge arms; a rectifier circuit having an input end coupled to the power supply and an output end connected to a first auxiliary power supply; and a controller coupled to the first auxiliary power supply and the plurality of switches of the second bridge arm to control corresponding switches of the second bridge arm, the power supply charges the flying capacitor through the corresponding switches of the first and second bridge arms and the first current limiting circuit.

Abstract: The application provides a power supply device comprising two input ports disposed at a front end of the power supply device; at least one fan disposed behind the two input ports and two isolated power supplies connected respectively to the corresponding one of the two input ports and disposed behind the two input ports and the at least one fan. Each of the isolated power supplies comprises a main power circuit having at least one module, and each module comprises a PCB and a magnetic element and/or switching devices. The at least one module includes an isolated circuit module comprises a transformer having windings formed by laying copper in the PCB and the magnetic core fixed on the PCB. And at least one fan is configured for heat dissipation of the at least one module.

Abstract: An engine balancing system includes an engine body. At least two slider-crank mechanisms are provided inside the engine body. One of the slider-crank mechanisms is arranged opposite to the other slider-crank mechanism. A slider in one of the slider-crank mechanisms is moved at a speed and acceleration similar to a speed and acceleration of a slider in the other slider-crank mechanism. The slider-crank mechanism includes a connecting rod and a crankshaft with a crank. One end of one of the slider-crank mechanisms and one end of the other slider-crank mechanism are connected to the same crankshaft through the crank. The balancing system can effectively eliminate first-order, second-order and higher-order vibrations generated during engine operation, thus reducing the probability of equipment damage.