Abstract: A video service quality assessment method and apparatus are provided to resolve a prior-art problem of relatively low accuracy of an assessment result. A monitoring device obtains an identifier of a to-be-monitored channel, an identifier of to-be-monitored user equipment, and configuration information of a video service transmission system; obtains a multicast video stream of the to-be-monitored channel based on the identifier of the to-be-monitored channel; obtains a retransmitted video stream based on the identifier of the to-be-monitored channel, the identifier of the to-be-monitored user equipment, and the configuration information of the video service transmission system; determines a to-be-assessed video stream based on the multicast video stream and the retransmitted video stream; and parses the to-be-assessed video stream, and obtains an assessment result based on a parsing result and the configuration information of the video service transmission system.

Abstract: A video service quality assessment method and apparatus, where a monitoring device is configured to: obtain an identifier of a to-be-monitored channel, an identifier of to-be-monitored user equipment, and configuration information of a video service transmission system; obtain a multicast video stream of the to-be-monitored channel based on the identifier of the to-be-monitored channel; obtain a retransmitted video stream based on the identifier of the to-be-monitored channel, the identifier of the to-be-monitored user equipment, and the configuration information of the video service transmission system; determine a to-be-assessed video stream based on the multicast video stream and the retransmitted video stream; parse the to-be-assessed video stream; and obtain an assessment result based on a parsing result and the configuration information of the video service transmission system.

Abstract: An online system predicts, using a first targeting model, a first group of users as candidates to be in a targeting cluster, and predicts, using a second targeting model, a second group of users as candidates to be in the targeting cluster. The online system determines a first set of users that are not part of the first group of users, and a second set of users that are not part of the second group of users, and provides surveys to the first and second set of users. The online system determines a first subgroup of the first group of users and a second subgroup of the second group of users, and provides an ad preferences tool to the first subgroup and the second subgroup. The online system scores the first and second targeting models based in part on responses to the surveys and/or the ad preferences tools.

Abstract: This application discloses a data transmission method, a sending device, a receiving device, and a communications system. The sending device is configured to send a first transport block. The sending device obtains a coded bit segment from a first encoded code block. The first encoded code block is obtained after LDPC encoding is performed on a first code block in the first transport block based on a processing capability of the receiving device. The sending device sends the coded bit segment to the receiving device. Because the processing capability of the receiving device is considered, storage overheads of the sending device or the receiving device can be reduced, encoding or decoding complexity can be reduced, and a decoding success rate can be improved.

Abstract: A method and an apparatus for detecting a scene change frame in a video and a system, where when a scene change frame in the video is detected, whether a maximum P frame (Pmax) in all P frames in a group of pictures (GOP) of the video is a scene change frame is determined based on a relative relationship between a size Pkmax of Pmax and a median or an average of sizes of a plurality of I frames between Pmax and a scene change frame closest to Pmax and before Pmax, or a relative relationship between Pkmax and a median or an average of sizes of a plurality of P frames in the GOP to detect a scene change frame in the P frames such that missed detection of a scene change frame is effectively reduced.

Abstract: The present invention discloses a method, an apparatus, and a system for implementing video quality assessment. When video quality is assessed, a proportion of a damaged data caused by packet loss in a video frame in which the damaged data is located is considered, and other factors are also considered, such as a position of the damaged data in the video frame and impact of a scene in which the video frame is located on the video frame or a video frame located after the video frame. Therefore, accuracy of quality assessment is higher.

Abstract: A method for preparing an ultrathin two-dimensional (2D) monocrystalline nanosheet, the method including: 1) placing BiX3 powder where X=I, Br, or Cl in a crucible, and putting the crucible on a first heating zone of a furnace disposed at a gas inlet of a quartz tube; placing substrates covered with metal sheets on a second heating zone of the furnace disposed at a gas outlet of the quartz tube; 2) vacuumizing the quartz tube; pumping Ar gas into the quartz tube until the air pressure is 101.325 kPa; pumping a carrier gas into the quartz tube; and 3) heating and maintaining the second heating zone; heating the first heating zone for BiX3 evaporation until producing chemical reaction between BiX3 and the metal sheets, and preparing ultrathin 2D nanosheets on the substrates simultaneously; and cooling the substrate naturally to 15-30° C.

Abstract: A video quality assessment method includes obtaining a video quality assessment parameter of a to-be-assessed video, where the video quality assessment parameter of the to-be-assessed video includes an average packet loss gap of the to-be-assessed video, determining packet loss dispersion of the to-be-assessed video based on the video quality assessment parameter of the to-be-assessed video, and determining quality of the to-be-assessed video based on a packet loss rate of the to-be-assessed video, an average consecutive packet loss length of the to-be-assessed video, the packet loss dispersion of the to-be-assessed video, and attribute information of the to-be-assessed video. Therefore, during video quality assessment, impact of packet loss distribution indicated by the packet loss dispersion on the video quality is considered.

Abstract: A hot live video determining method is provided. A network device first obtains a plurality of video request messages for a target video; then determines statistical information of the target video based on the plurality of video request messages, where the statistical information includes a quantity of video request messages for the target video that are obtained in specified duration and fragment information of a video fragment requested in each video request message; and finally determines, based on the statistical information, whether the target video is a hot live video. According to the method, the network device can identify the hot live video in the Internet, so the network device can carry the hot live video in a multicast manner, to avoid breakdown that is of a network and a video server and that is caused by transmitting the hot live video in a unicast method.

Abstract: When video quality is assessed, a proportion of a damaged data caused by packet loss in a video frame in which the damaged data is located is considered, and other factors are also considered, such as a position of the damaged data in the video frame and impact of a scene in which the video frame is located on the video frame or a video frame located after the video frame. Therefore, accuracy of quality assessment is higher.

Abstract: A video quality assessment method includes obtaining a video quality assessment parameter of a to-be-assessed video, where the video quality assessment parameter of the to-be-assessed video includes an average packet loss gap of the to-be-assessed video, determining packet loss dispersion of the to-be-assessed video based on the video quality assessment parameter of the to-be-assessed video, and determining quality of the to-be-assessed video based on a packet loss rate of the to-be-assessed video, an average consecutive packet loss length of the to-be-assessed video, the packet loss dispersion of the to-be-assessed video, and attribute information of the to-be-assessed video.

Abstract: A split roller cone and polycrystalline diamond compact (PDC) composite drill bit, including a PDC bit module, a split roller cone bit module, and a drill bit body module. The split roller cone bit module has split structure, and during the operation, the lower roller cone body and the upper roller cone body revolve with the drill bit, and rotate around the axle neck of the palm respectively, thereby achieving the task of scraping and breaking rocks. The tooth scraping efficiencies of the small-end ring gear and the middle ring gear are improved. The split roller cone bit module, the PDC bit module, and the drill bit body module can be mass-produced. The split roller cone bit module and the PDC bit module can be quickly assembled and disassembled with the drill bit body module and different sizes of PDC bit modules are assembled with the bit body module.

Abstract: This application discloses an information processing method. A communication device obtains an input sequence. The input sequence has a quantity B of bits. The communication devices transforms the input sequence into one or more code blocks. The communication device encodes each of the code blocks, to obtain one or more encoded code blocks. Each of the code blocks has a code block length less than or equal to a maximum code block length. Each of the code blocks includes a segment of the input sequence, one or more cyclic redundancy check (CRC) bits corresponding to the segment of the input sequence, and one or more filler bits. The encoded code blocks can meet various channel coding requirements.

Abstract: A device for measuring surface-temperature of a turbine blade, the device including a probe having a front-end mirror for receiving infrared radiation of a surface on the blade, a collimation lens for refracted the infrared radiation, a PD detector to receive the infrared radiation, and a focal-length servo; and a radial-scanning servo connected to the probe. The front-end mirror, the collimation lens, and PD detector are disposed along the optical axis of the collimation lens. The focal-length servo is adapted to move the collimation lens along the optical axis of the collimation lens. The radial-scanning servo is adapted to move the probe along the optical axis of the collimation lens. The device of the invention is capable of accurately targeting a particular point on the blade having an irregular shape for temperature measurement to accurately detect the temperature distribution on the surface of the blade.

Abstract: This application discloses an information processing method. A communication device obtains an input sequence. The input sequence has a quantity B of information bits. The communication devices transforms the input sequence into one or more code blocks. The communication device encodes each of the code blocks individually, to obtain one or more encoded code blocks. Each of the code blocks has a code block length less than or equal to a maximum code block length. Each of the code blocks includes a segment of the input sequence and may include one or more cyclic redundancy check (CRC) bits corresponding to the segment of the input sequence. The encoded code blocks can meet various channel coding requirements.

Abstract: A video quality assessment method and device are provided. The video quality assessment method includes: obtaining a to-be-assessed video, where the to-be-assessed video includes a forward error correction (FEC) redundancy data packet; when a quantity of lost data packets of a first source block in the to-be-assessed video is less than or equal to a quantity of FEC redundancy data packets of the first source block, generating a first summary packet for a non-lost data packet of the first source block, and generating a second summary packet for a lost data packet of the first source block; and calculating a mean opinion score of video (MOSV) of the to-be-assessed video based on the first summary packet and the second summary packet. The MOSV calculated according to the method is more consistent with real video experience of a user, so accuracy of video quality assessment can be improved.

Abstract: A split roller cone and polycrystalline diamond compact (PDC) composite drill bit, including a PDC bit module, a split roller cone bit module, and a drill bit body module. The split roller cone bit module has split structure, and during the operation, the lower roller cone body and the upper roller cone body revolve with the drill bit, and rotate around the axle neck of the palm respectively, thereby achieving the task of scraping and breaking rocks. The tooth scraping efficiencies of the small-end ring gear and the middle ring gear are improved. The split roller cone bit module, the PDC bit module, and the drill bit body module can be mass-produced.

Abstract: This application discloses a data transmission method, a sending device, a receiving device, and a communications system. The sending device is configured to send a first transport block. The sending device obtains a coded bit segment from a first encoded code block. The first encoded code block is obtained after LDPC encoding is performed on a first code block in the first transport block based on a processing capability of the receiving device. The sending device sends the coded bit segment to the receiving device. Because the processing capability of the receiving device is considered, storage overheads of the sending device or the receiving device can be reduced, encoding or decoding complexity can be reduced, and a decoding success rate can be improved.

Abstract: A method and an apparatus for detecting a scene change frame in a video and a system, where when a scene change frame in the video is detected, whether a maximum P frame (Pmax) in all P frames in a group of pictures (GOP) of the video is a scene change frame is determined based on a relative relationship between a size Pkmax of Pmax and a median or an average of sizes of a plurality of I frames between Pmax and a scene change frame closest to Pmax and before Pmax, or a relative relationship between Pkmax and a median or an average of sizes of a plurality of P frames in the GOP to detect a scene change frame in the P frames such that missed detection of a scene change frame is effectively reduced.