Abstract: A registration method and an electronic device for visual navigation in dental implant surgery, comprising obtaining a three-dimensional model of a target tooth to be registered, an entity model of the target tooth and a second model of the target tooth, obtaining a position and attitude matrix of the three-dimensional model in a virtual coordinate system according to the coordinates of at least three points on a three-dimensional model of a substrate after the registration of the three-dimensional model in the virtual coordinate system, mounting the entity model of the target tooth onto a registration standard board, obtaining a position and attitude matrix of the entity model in the visual coordinate system according to three optical marks and the points on the entity model corresponding to the three points, and obtaining a correspondence between the virtual coordinate system and the visual coordinate system according to two position and attitude matrices.

Abstract: A method of preparing PAN-based carbon fibers relates to the technical field of materials. The method includes: S1. acrylonitrile, a second monomer and an unsaturated UV-sensitive cross-linking agent are mixed, an initiator is then added and a reaction is performed to obtain a meltable PAN-based copolymer; S2. the meltable PAN-based copolymer and a flow modifier are mixed to obtain a mixture, the mixture is extruded and pelletized, and then melt spinning is performed to obtain nascent fibers, the nascent fibers are stretched and annealed to obtain a PAN-based carbon fiber precursor; S3. ultraviolet irradiation is performed on the PAN-based carbon fiber precursor; S4. the PAN-based carbon fiber precursor after ultraviolet irradiation is pre-oxidized and carbonized to obtain PAN-based carbon fibers.

Abstract: The present disclosure provides a technical solution related to intelligent knowledge learning and question-answering. The technical solution involves extracting knowledge from corpus and providing a user with a question-answering service based on the extracted knowledge.

Abstract: Determining an active jacking force of a tunneling closely undercrossing existing station, includes: acquiring design parameters of stations, and geological parameters of a construction site; obtaining a stress solution expression of the active jacking force on the existing station to obtain a stress solution of any point in a semi-infinite space under the action of a vertical load, replacing the vertical load with a vertical load acting on the existing station, and obtain a vertical stress solution of the existing station; obtaining a relational expression between the deflection and the stress solution of the existing station; and substituting the stress solution expression of the active jacking force into the relational expression between the deflection and the stress solution of the existing station according to boundary conditions at both ends of a beam on elastic foundation to obtain the active jacking force that controls the deflection of the existing station.

Abstract: Disclosed is a denture tray for visual marking and a manufacturing method thereof. The method comprises: establishing a three-dimensional model of a target dentition of a target patient; obtaining a three-dimensional model of a substrate of a denture tray based on the three-dimensional model of the target dentition; providing a through hole at a preset position on the three-dimensional model of the substrate of the denture tray; establishing a three-dimensional model of a fixed connection portion on an outer side surface of the three-dimensional model of the substrate of the denture tray to form a three-dimensional model of the denture tray, wherein the three-dimensional model of the fixed connection portion is integrally connected with the three-dimensional model of the substrate of the denture tray; and manufacturing the denture tray based on the three-dimensional model of the denture tray.

Abstract: A method and a system for constructing a driving coordinate system for use in the field of smart transport. The method for constructing a driving coordinate system comprises: determining the road boundary line on one side of the road on which a current vehicle is situated as a reference line for constructing a driving coordinate system; in a vehicle coordinate system, determining the reference line point having the smallest distance between the reference line and the current vehicle position as an origin point OF of the driving coordinate system; on the basis of the origin point OF, determining the road guiding line direction as the XF axis of the driving coordinate system and determining the direction relative to the road guiding line direction according to the left-hand rule as the YF axis of the driving coordinate system; and, on the basis of the origin point OF, the XF axis, and the YF axis, forming a corresponding driving coordinate system.

Abstract: A method for controlling lane changing of a vehicle, including: receiving a lane changing instruction (step 101); acquiring a speed parameter of the vehicle (step 102); according to the speed parameter, determining a controlling coefficient of a predetermined controller (step 103); acquiring a position-deviation parameter and a heading-angle parameter of the vehicle; if the position-deviation parameter is greater than or equal to a first threshold, or, if the heading-angle parameter is greater than or equal to a second threshold, according to the controlling coefficient, the position-deviation parameter and the heading-angle parameter, determining a target steering-wheel steering angle of the vehicle; and according to the target steering-wheel steering angle, controlling the vehicle to perform a lane changing operation, till the position-deviation parameter is less than the first threshold, and the heading-angle parameter is less than the second threshold (step 105).

Abstract: A method for extracting and isolating a lutein crystal from a vegetable oil resin containing a lutein diester, comprises: dissolving lipase into deionized water to form an enzyme solution; dissolving a lutein extract into an alcohol solvent containing the deionized water to form a uniform alcohol solution; adding the enzyme solution to the alcohol solution for performing hydrolysis, and stirring same to obtain a lutein solution; filtering and performing filtration isolation on the lutein solution to obtain a crystalline; re-dissolving the crystalline into a non-polar organic solvent, and using deionized water for washing a water-soluble impurity; recycling and cooling the organic solvent to obtain a recrystallization; and isolating and drying the recrystallization to obtain the lutein crystal. In this method, selectivity is strong, reaction time is short, no waste water is produced, process is environment-friendly and suitable for industrial production, and obtained lutein crystal is high in purity and yield.

Abstract: A thermal recovery construction method includes the steps of determining design parameters of a current thermal recovery construction according to geological data and reservoir characteristics of a current oil deposit area to be stimulated; preparing, according to the design parameters, coal water slurry required for the current thermal recovery construction; injecting the coal water slurry into a target reservoir through an injection well with an injection mode of the design parameters, along with combustion adjuvant with an amount selected based on a total injection amount of the coal water slurry; and inducing spontaneous combustion of the coal water slurry by thermal energy generated by a downhole heating device, and performing control and displacement on the reservoir with the thermal energy and gas generated after the combustion.

Abstract: An off-road vehicle includes a frame; front and rear wheels; a front suspension assembly; a front torsion bar assembly, a rear suspension assembly and a rear torsion bar assembly. The front suspension assembly comprises a front lower rocker arm, a front upper rocker arm, and a front wheel shaft support assembly mounted between the front lower and the front upper rocker arms. The front torsion bar assembly is located above the front upper rocker arm, and is movably connected to the front upper rocker arm. The rear suspension assembly comprises a rear lower rocker arm, a rear upper rocker arm, a control arm assembly, and a rear wheel shaft support assembly mounted between the rear lower and rear upper rocker arms. The rear torsion bar assembly is located between the rear upper and lower rocker arms, and is movably connected to the rear upper rocker arm.

Abstract: The present disclosure provides a method and an apparatus for providing responses in an event-related session. The event is associated with a predefined domain, and the session comprises an electronic conversational agent and at least one participant. At least one message from the at least one participant may be detected. A set of candidate responses may be retrieved, from an index set being based on the domain, according to the at least one message. The set of candidate responses may be optimized through filtering the set of candidate responses according to predetermined criteria. A response to the at least one message may be selected from the filtered set of candidate responses. The selected response may be provided in the session.

Abstract: A knowledge graph embedding representation method and a related device are disclosed. The method includes: obtaining, from a preset knowledge base, N related entities of each entity in M entities of a target knowledge graph and K concepts corresponding to each of the N related entities, determining a semantic correlation between each entity and each of the N related entities of the entity, determining a first entity embedding representation of each of the N related entities based on the corresponding K concepts, modeling, based on the first entity embedding representation and the semantic correlation, an entity/relationship embedding representation, and training a model according to an attention mechanism and a preset model training method, to obtain the entity/relationship embedding representation.

Abstract: The present disclosure discloses a technique of recommending news in conversation. The technique may recommend news in a conversation with respect to the case that a user may be interested in some news event during a conversation, so that the user's interests in reading news may be found during the conversation, and provides the user with related new information on news in a form of chatting reply at appropriate time.

Abstract: The present disclosure provides a technical solution related to intelligent knowledge learning and question-answering. The technical solution involves extracting knowledge from corpus and providing a user with a question-answering service based on the extracted knowledge.

Abstract: A laser level ruler, comprising a housing (1). A laser emission module (2), a ranging module (5), a power supply module (4) and an angle measurement module (3) are arranged in the housing (1), wherein the power supply module (4) supplies power to the laser emission module (2), the ranging module (5) and the angle measurement module (4); the laser emission module (2) and the ranging module (5) are arranged at both ends of the housing; and the power supply module (4) and the angle measurement module (3) are arranged between the laser emission module (2) and the ranging module (5).

Abstract: A frame averaging circuit adapted for a color blood flow frame in a medical ultrasound imaging system. The frame averaging circuit comprises two sections, i.e., a recursive calculation section and a non-recursive section. The recursive calculation section employs an IIR filter in combination with a look-up table, and is adapted for dealing with the cases where no change occurs to the blood flow velocity direction. The non-recursive section compares the blood flow velocity, the energy and the energy prior to wall filtering of the color blood flow echo signal to various threshold values. Different from the recursive calculation section, the non-recursive section is employed when a change occurs to the blood flow velocity direction.

Abstract: A method for Doppler scan conversion includes storing coded envelope values together with spectrum data in a memory out of a logic device with a large capacity, which increases the number of envelopes stored, reduces the use of the restricted embedded memory resources, and can also achieve the envelope switching more flexibly. If the number of envelopes is not greater than the difference between the bit width of the memory and that of the spectrum data, the increase in the number of envelopes will not increase significantly the logic resources or affect the efficiency of the system.

Abstract: A frame averaging circuit adapted for a color blood flow frame in a medical ultrasound imaging system. The frame averaging circuit comprises two sections, i.e., a recursive calculation section and a non-recursive section. The recursive calculation section employs an IIR filter in combination with a look-up table, and is adapted for dealing with the cases where no change occurs to the blood flow velocity direction. The non-recursive section compares the blood flow velocity, the energy and the energy prior to wall filtering of the color blood flow echo signal to various threshold values. Different from the recursive calculation section, the non-recursive section is employed when a change occurs to the blood flow velocity direction.

Abstract: The present invention relates to a method and apparatus for judging an unnecessary windward condition and a method and system for tracking wind, wherein the method comprises: taking a first wind sample by using a wind sampling-detecting unit, detecting and obtaining a wind direction thereof; judging whether an intersection angle between the first wind direction and a current wind turbine orientation is smaller than a critical angle of rotation; if “yes”, determining the windward condition is unnecessary windward condition; if “no”, detecting a wind speed of the first wind sample, judging whether the detected wind speed is lower than a first critical wind speed; if “yes”, determining the windward condition is unnecessary windward condition; if “no”, determining the windward condition is not unnecessary windward condition, then rotating the cabin of the wind power generating set, thereby achieving accurate windward according to a wind condition, a cabin position, and so on.

Abstract: A method for Doppler scan conversion includes storing coded envelope values together with spectrum data in a memory out of a logic device with a large capacity, which increases the number of envelopes stored, reduces the use of the restricted embedded memory resources, and can also achieve the envelope switching more flexibly. If the number of envelopes is not greater than the difference between the bit width of the memory and that of the spectrum data, the increase in the number of envelopes will not increase significantly the logic resources or affect the efficiency of the system.