Abstract: The present disclosure provides a phase-locked loop, a frequency divider and a communication device that enable fast locking. The phase-locked loop comprises a phase frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, a fast-locking control unit and a frequency divider, wherein the frequency divider comprises a plurality of cascaded frequency division units and a reset/set control circuit, the reset/set control circuit being configured to receive the reset signal outputted by the fast-locking control unit, and in response to transition of the reset signal from a low level to the high level, change a state code combination composed of respective state codes of the cascaded frequency division units from the first state to the second state, to cause transition of a feedback signal outputted by the frequency divider from the low level to the high level. With the frequency divider and phase-locked loop, fast locking can be achieved.

Abstract: A cell culture structure and a cell culture device are provided. The cell culture structure includes a substrate having a top surface and a bottom surface. A plurality of micro recesses are recessed from the top surface toward the bottom surface of the substrate, in which a recess width of each of the micro recesses decreases from the top surface toward the bottom surface to form an inclined sidewall. The inclined sidewall of each of the micro recesses is formed with a nano structure conforming to and covering a three-dimensional contour of the corresponding micro recess. Each of the micro recesses and the corresponding nano structure collectively form a three-dimensional culture space.

Abstract: In some embodiments, a method sends a set of first requests for a set of first segments of a video in a playback session. A first protocol from a plurality of protocols is specified in at least one of the set of first requests. The set of first segments is received. The method determines whether to switch from using the first protocol to a second protocol in the playback session based on receiving the set of first segments. When switching to the second protocol, the method sends a second request in the playback session, wherein the second request indicates the second protocol is to be used to send a second segment of the video.

Abstract: The present disclosure provides a phase-locked loop, a frequency divider and a communication device that enable fast locking. The phase-locked loop comprises a phase frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, a fast-locking control unit and a frequency divider, wherein the frequency divider comprises a plurality of cascaded frequency division units and a reset/set control circuit, the reset/set control circuit being configured to receive the reset signal outputted by the fast-locking control unit, and in response to transition of the reset signal from a low level to the high level, change a state code combination composed of respective state codes of the cascaded frequency division units from the first state to the second state, to cause transition of a feedback signal outputted by the frequency divider from the low level to the high level. With the frequency divider and phase-locked loop, fast locking can be achieved.

Abstract: In some embodiments, after receiving a first set of video segments of a video, a method starts a first computing instance and receives a video segment of the video using the first computing instance. A measurement is calculated based on receiving the video segment. The method uses the measurement to determine whether the first computing instance should continue to be used to receive video segments in the video or should be terminated to not receive video segments in the video.

Abstract: A fast-locking phase-locked loop comprises a phase frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, a frequency divider, and a fast-locking control unit which receives a reference clock signal at its first input terminal and a phase-locking enable signal at its second input terminal and outputs a reset signal at a high level in response to a rising edge of the reference clock signal when receiving the phase-locking enable signal, wherein the frequency divider is connected to an output terminal of the fast-locking control unit and configured to trigger generation of a feedback signal in response to the reset signal at the high level, and the phase frequency detector is connected to the output terminal of the fast-locking control unit and configured to output a phase error between the reference clock signal and the feedback signal in response to the reset signal at the high level.

Abstract: A fast-locking phase-locked loop comprises a phase frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, a frequency divider, and a fast-locking control unit which receives a reference clock signal at its first input terminal and a phase-locking enable signal at its second input terminal and outputs a reset signal at a high level in response to a rising edge of the reference clock signal when receiving the phase-locking enable signal, wherein the frequency divider is connected to an output terminal of the fast-locking control unit and configured to trigger generation of a feedback signal in response to the reset signal at the high level, and the phase frequency detector is connected to the output terminal of the fast-locking control unit and configured to output a phase error between the reference clock signal and the feedback signal in response to the reset signal at the high level.

Abstract: In some embodiments, a method sends a set of first requests for a set of first segments of a video in a playback session. A first protocol from a plurality of protocols is specified in at least one of the set of first requests. The set of first segments is received. The method determines whether to switch from using the first protocol to a second protocol in the playback session based on receiving the set of first segments. When switching to the second protocol, the method sends a second request in the playback session, wherein the second request indicates the second protocol is to be used to send a second segment of the video.

Abstract: The present disclosure relates to a fractional frequency divider, a radio frequency transceiver, and a method of configuring a phase delay in the fractional frequency divider. The fractional frequency divider comprises a counter, a multiplexer, and a delay module. The method is applicable to the fractional frequency divider. The radio frequency transceiver comprises the fractional frequency divider, and the fractional frequency divider adopts the method. According to the aforesaid technical solution, the present disclosure has advantages as follows: the embodiments of the present disclosure can minimize the timing inaccuracy and suppress the output jitter and output spurs; and the embodiments of the present disclosure can effectively extend the operating frequency range of the fractional frequency divider.

Abstract: The present disclosure relates to a fractional frequency divider, a radio frequency transceiver, and a method of configuring a phase delay in the fractional frequency divider. The fractional frequency divider comprises a counter, a multiplexer, and a delay module. The method is applicable to the fractional frequency divider. The radio frequency transceiver comprises the fractional frequency divider, and the fractional frequency divider adopts the method. According to the aforesaid technical solution, the present disclosure has advantages as follows: the embodiments of the present disclosure can minimize the timing inaccuracy and suppress the output jitter and output spurs; and the embodiments of the present disclosure can effectively extend the operating frequency range of the fractional frequency divider.

Abstract: In some embodiments, a method sends a set of requests for a video using a first protocol. The first protocol is selected from a plurality of protocols available for use in a playback session for the video. The method compares a first performance of the first protocol and a second performance of a second protocol and determines whether to switch from using the first protocol to the second protocol in the playback session based on the comparing.

Abstract: In some embodiments, after receiving a first set of video segments of a video, a method starts a first computing instance and receives a video segment of the video using the first computing instance. A measurement is calculated based on receiving the video segment. The method uses the measurement to determine whether the first computing instance should continue to be used to receive video segments in the video or should be terminated to not receive video segments in the video.

Abstract: In some embodiments, a method receives a plurality of video segments of a video using a plurality of computing instances and measures data received for the plurality of computing instances during a time window. A video segment for a computing instance in the plurality of computing instances is not fully downloaded during the time window. The method calculates a video delivery metric for the plurality of computing instances based on the data received and calculates an evaluation measurement based on the video delivery metric. The evaluation measurement is used to control an addition or a termination of a computing instance.

Abstract: The present disclosure provides a multi modulus frequency divider and an electronic device. The duty cycle adjusting circuit in the multi modulus frequency divider is configured to generate a second output clock signal according to a first output clock signal and an input modulus signal received by one or more frequency division units, the frequency of the second output clock signal is the same as that of the first output clock signal, and the duty cycle of the second output clock signal is different from that of the first output clock signal. The duty cycle of the clock signal output by the multi modulus frequency divider provided in the present disclosure is generally closer to 50%.

Abstract: In some embodiments, a method receives a plurality of video segments of a video using a plurality of computing instances and measures data received for the plurality of computing instances during a time window. A video segment for a computing instance in the plurality of computing instances is not fully downloaded during the time window. The method calculates a video delivery metric for the plurality of computing instances based on the data received and calculates an evaluation measurement based on the video delivery metric. The evaluation measurement is used to control an addition or a termination of a computing instance.

Abstract: In some embodiments, a method sends a set of requests for a video using a first protocol. The first protocol is selected from a plurality of protocols available for use in a playback session for the video. The method compares a first performance of the first protocol and a second performance of a second protocol and determines whether to switch from using the first protocol to the second protocol in the playback session based on the comparing.

Abstract: The invention provides a safety injector needle. The safety injector needle includes a needle seat, an injection needle axially fixedly connected to the needle seat, and a trigger protection assembly assembled on the needle seat, the needle seat includes an assembly part and a fixing part; the trigger protection assembly includes a case, a trigger mechanism and an elastic element; the case is arranged in a hollow tube shape; the trigger mechanism includes a first trigger mechanism and a second trigger mechanism. The first trigger mechanism can slide along the extension direction of the case under the action of the elastic element.; the second trigger mechanism can slide along the extension direction of the needle seat under the action of the elastic element, so that the injection needle is completely contained between the trigger mechanism and the needle seat after the safety injector needle is used.

Abstract: In some embodiments, a method receives one or more segments for content from a first content delivery network during a playback session for the content. The content includes a number of segments. The method evaluates buffer occupancy of a buffer configured to store segments of the content for playback and evaluates a number of times of a failure to download a segment for the content. The buffer occupancy is compared to a first threshold and the number of times of the failure to a second threshold. The method determines a switch from the first content delivery network to a second content delivery network during the playback session based on the comparing.

Abstract: A manufacturing method, Printed Circuit Board (PCB) panel, and a PCB are disclosed. The method includes forming a cavity in a PCB that is in a PCB panel that includes a frame and stays, mounting an electronic component, heating the PCB panel, and cutting the stays. The PCB panel includes a frame body and a PCB coupled to the frame body via stays. The PCB includes a cavity. A first cavity stay is located near the cavity. Extended lines extend from the cavity, and the cavity stay extends at least between the extended lines. The PCB includes a cavity and a connection point from a cavity stay near the cavity.

Abstract: In some embodiments, a method receives one or more segments for content from a first content delivery network during a playback session for the content. The content includes a number of segments. The method evaluates buffer occupancy of a buffer configured to store segments of the content for playback and evaluates a number of times of a failure to download a segment for the content. The buffer occupancy is compared to a first threshold and the number of times of the failure to a second threshold. The method determines a switch from the first content delivery network to a second content delivery network during the playback session based on the comparing.