Abstract: This application provides a signal transmission method, apparatus, and system. The method includes: generating an ultra-wideband signal, where the ultra-wideband signal includes a channel impulse response training sequence (CTS) field, and the CTS field is obtained by separately spreading at least one first preamble symbol based on a pseudo-random sequence; and sending the ultra-wideband signal, where the CTS field is used to determine a channel impulse response. This application can effectively improve ranging and positioning efficiency while implementing secure high-precision ranging and positioning.

Abstract: An initiating device randomly generates a sending time interval at which the initiating device sends ranging signal frames to a responding device such that an attacker cannot determine a rule of sending the ranging signal by the initiating device to the responding device and cannot send an interference signal at a same moment to perform interference and an attack, thereby enhancing information security of electronic devices during interactive communication.

Abstract: The present disclosure relates to signal transmission methods, apparatuses, and systems. One example method includes sending a narrow band signal to a receive end, where the narrow band signal is used by the receive end to determine initial time-frequency synchronization information, and sending an ultra-wideband signal to the receive end, where the ultra-wideband signal includes a channel impulse response training sequence (CTS) field, the CTS field is used by the receive end to determine a channel impulse response, the CTS field includes at least one CTS symbol, and the CTS symbol includes at least one first preamble symbol or is generated by spreading at least one first preamble symbol.

Abstract: An underwater debris suction apparatus includes a power device and a filter device. The power device includes a suction component and a power drive device configured to provide power for the suction component. The underwater debris suction apparatus further includes a collection device, and the upper end of the collection device is provided with an opening. The suction component is at least partially located above the filter device or is entirely located in the space of the filter device. During operation of the suction component, unfiltered pool water enters the filter device through a water inlet channel and flows to the side wall of the filter device, so that the filtered water is discharged from the side wall of the filter device, and the debris that cannot be discharged from the side wall of the filter device falls into the collection device.

Abstract: In a method for sending signals in network communications, an apparatus obtains a plurality of extended sequences, with each extended sequence comprising an original sequence and an additional sequence. In each extended sequence, the additional sequence is located before the original sequence, and the additional sequence includes last m codes of the original sequence. Alternatively, the additional sequence is located after the original sequence, and the additional sequence includes first n codes of the original sequence. The apparatus generates a plurality of target sequences based on the plurality of extended sequences and a security code corresponding to each extended sequence. The apparatus then generates a first impulse signal based on the plurality of target sequences, and sending the first impulse signal.

Abstract: A secure ranging method and an apparatus are provided. The method includes: a receiving-end device and a transmitting-end device obtain a session key through a narrowband system. The devices of both parties further generate secure CTSs in a symmetric manner based on the session key in combination with CTS configuration information, and perform inter-device ranging in a UWB system by using the CTSs. According to this application, the CTS can be flexibly configured based on the CTS configuration information, to improve secure ranging performance. In addition, the narrowband system replaces the UWB system to perform key-related information negotiation, and ranging is performed in the UWB system, so that high-accuracy ranging is implemented while low power consumption is considered.

Abstract: The present disclosure relates to signal transmission methods and apparatuses. One example method includes spreading a preamble symbol based on a first spreading code sequence to generate a first signal, and sending the first signal to a receiver. The first signal is used to determine a channel impulse response. The first spreading code sequence includes a plurality of spreading code groups, each spreading code group includes a plurality of same spreading codes and at least one guard symbol, at least one of a first bit or a last bit of each spreading code group is a guard symbol, and the plurality of spreading code groups include at least two spreading code groups with different spreading codes.

Abstract: This application provides example ultra-wideband (UWB) signal synchronization methods and example communication apparatuses. One example method includes processing a narrowband signal to obtain time-frequency synchronization information of the narrowband signal. A synchronization signal of an UWB signal can be processed based on the time-frequency synchronization information of the narrowband signal to obtain time-frequency synchronization information of the UWB signal, where the UWB signal includes the synchronization signal and a ranging signal. The ranging signal can be received based on the time-frequency synchronization information of the UWB signal.

Abstract: A clock synchronization method includes sending a narrowband synchronization frame via a narrowband system, to complete coarse clock synchronization in a wideband system; and sending a wideband frame after duration, allocated by the narrowband system, for switching from a narrowband to a wideband ends, to complete fine clock synchronization in the wideband system.

Abstract: Example ranging methods and apparatus are described. In one example method, a first device sends ranging control information to a second device through a first channel, where the ranging control information is used to configure a ranging frame. The first device receives or sends the ranging frame through a second channel, where a bandwidth of the second channel is greater than a bandwidth of the first channel. Based on the foregoing solution, the first device and the second device may exchange the ranging control information and a measurement result through the first channel, and perform ranging through the second channel.

Abstract: Provided are a use of recombinant calreticulin in hair growth, hair breeding, hair protection or anti-hair loss and a related product. The recombinant protein is derived from the full length of calreticulin or a fragment thereof, and has the functions of treating hair loss and improving hair by means of injection or application. Therefore, calreticulin is expected to be developed into an effective method and means for treating hair loss and improving hair.

Abstract: Disclosed are apparatus, electronic device, and method for stitching dual-camera images. The method includes collecting two images having overlapping photographic content. The method includes extracting and matching feature points of the two images. The method includes roughly aligning the two images by using a homography matrix. The method includes accurately aligning the two images by using a least squares method to complete stitching the two images.

Abstract: An obstacle touching detecting device for a swimming pool cleaner includes a main functional portion of the cleaner and a sensor obstacle touching detecting device. The main functional portion of the cleaner includes a cleaner main body, a controller module, and a power-driven actuating device. The controller module and the power-driven actuating device are connected to the cleaner main body. The sensor obstacle touching detecting device includes a trigger unit connected to the cleaner main body and a sensor detecting module electrically connected to the controller module. The controller module is electrically connected to the power-driven actuating device. The trigger unit works collaboratively with the sensor detecting module to trigger the sensor detecting module to generate a detection signal. An automatic detection is performed when the cleaner touches the wall or other obstacles, and the cleaner is controlled to change direction automatically.

Abstract: The present invention relates to a method for the prediction of the risk of developing preeclampsia in a pregnant human subject, wherein said subject's gestational age is under 140 days, comprising the steps of: (a) measuring in a sample from said subject a plurality of loci-specific DNA methylation levels; (b) deriving from said measurement a DNA methylation profile for said subject (c) comparing said DNA methylation profile to one or more reference DNA methylation profile(s) corresponding to preeclampsia risk group; and (d) assigning on the basis of said comparison said subject to a preeclampsia risk group, thereby predicting the risk of developing preeclampsia in said subject.

Abstract: Systems and methods to generate a model based on a subset of models generated at remote devices include a first device operatively coupled with a second device. The first device can generate, based on a model parameter and data restricted to the first device, a first model via machine learning, partition the first model into a plurality of local mask shares each including a distinct portion of the first model, encode one or more of the plurality of local mask shares into a corresponding first plurality of encoded shares, and generate an aggregation of encoded shares including a first encoded share having a first index among the first plurality of encoded shares and a second encoded share having the first index among a second plurality of encoded shares. The second encoded share includes a distinct portion of a second model generated by a second device via machine learning.

Abstract: A surface cleaning apparatus can include a housing adapted to move across a surface to be cleaned, an edge brush, and a brushroll driven by a brush motor. The edge brush is connectable with a drive coupling for rotating the edge brush, and is indirectly driven by the brush motor via the brushroll. In one aspect, the edge brush and drive coupling comprise a modular unit removably coupled to the housing. In another aspect, the drive coupling can include a worm and a belt.

Abstract: A five-axis linkage 3D printer is provided, and relates to the field of 3D printers. In the device, a base material driving unit is configured to drive and control a base material to rotate on a base; a nozzle driving unit is configured to control the position of a nozzle of the 3D printer in a horizontal direction and a vertical direction; a scanning unit is configured to scan and photograph movement trajectory of the base material and transmit information of the movement trajectory to an electric control system; and the electric control system is configured to collect the information of the scanning unit and controlling movement of the nozzle driving unit and the base material driving unit. With the device, the position of the nozzle is accurately controlled in x-axis direction, y-axis direction and z-axis direction, and a rotary table is placed inside a groove of the base.

Abstract: A merchant's mobility data from their mobile device and their purchase history from a wholesale supplier may be used for underwriting a business loan. The mobility data may be analyzed into several descriptive statistics, which may characterize, in a sense, the person's behavior patterns. A merchant's purchase history from a wholesale supplier may be analyzed to estimate several business performance statistics. The estimated performance statistics and the mobility statistics, when combined, may generate an insightful and very accurate profile of a borrower. A machine learning system may use statistics derived from purchasing history as well as mobility information to accurately calculate a confidence score, which may reflect a loan applicant's likelihood of fully repaying a loan. The confidence score may be compared to a threshold value to determine whether to grant or deny a loan. The threshold value may be dynamically updated to meet a loan portfolio's financial objectives.

Abstract: Some aspects of the subject matter disclosed herein include a system implemented on one or more data processing apparatuses. The system can include an interface configured to obtain, from one or more sensor subsystems, sensor data describing an environment of a vehicle, and to generate, using the sensor data, (i) one or more first neural network inputs representing sensor measurements for a particular object in the environment and (ii) a second neural network input representing sensor measurements for at least a portion of the environment that encompasses the particular object and additional portions of the environment that are not represented by the one or more first neural network inputs; and a convolutional neural network configured to process the second neural network input to generate an output, the output including a plurality of feature vectors that each correspond to a different one a plurality of regions of the environment.

Abstract: A mechanism for detecting obstacles and mechanically reversing (a direction of) a pool cleaner includes a drive part in non-rotatable connection with a cleaner housing, an arresting assembly connected to the cleaner housing, and a rotary direction-changing assembly rotatably connected to the cleaner housing or the drive part. The arresting assembly cooperates with the rotary direction-changing assembly. The mechanism for detecting obstacles and mechanically reversing (a direction of) a pool cleaner is compact in structure, low in manufacturing cost, and can perform obstacle detection and change a direction of the pool cleaner. With the structure of the rotary direction-changing assembly capable of rotating relative to the cleaner housing, the cleaner, when meeting an obstacle, is allowed to change the traveling direction, thereby resulting in a high working efficiency.