336results about How to "Good reference value" patented technology

The invention provides a CFD-based coronary artery blood flow simulating system and method. The simulating system comprises a Computed tomography (CT) data obtaining system, a blood vessel 3D model reconstruction system, a CFD pre-processing system, a CFD computation system and a post-processing system, wherein the CT data obtaining system obtains a CT image sequence of cardiovascular system of the human body; the blood vessel 3D model reconstruction system carries out 3D reconstruction on the extracted image sequence to obtain a 3D coronary-artery blood vessel model; the CFD pre-processing module carries out pre-processing required by hydrodynamic computation on the 3D coronary-artery blood vessel model; the CFD computation system resolves a 3D flow control equation of blood in the coronary artery blood vessel and outputs a computation result; and the post-processing system adds the computation result to the corresponding position of the 3D coronary-artery blood vessel model, and displays color cloud atlas. The coronary artery FFR is calculated and used as the standard for assessing the coronary artery function, disadvantages in determining the blood supply state of the cardiac muscle in the coronary artery anatomy aspect are overcome patients are not sound, and the cost is lower.

The invention discloses a performance test platform and method for a multi-rotor unmanned aerial vehicle. The test platform comprises a base, a stand column, a top frame, a performance test instrument and a calculation processing center; the bottom of the stand column is connected to the base through a ball-head universal bearing, and the top of the stand column is connected to the top frame through a ball-head universal bearing; the top frame is hung on an external rigid body through an elastic inhaul cable; a rack of the multi-rotor unmanned aerial vehicle is provided with a sleeving ring arranged on the stand column in a sleeving mode; the performance test instrument comprises an on-vehicle test instrument body which is arranged on the multi-rotor unmanned aerial vehicle and used for testing flight attitude information and work condition information of the multi-rotor unmanned aerial vehicle and a ground test instrument body which is arranged on the test platform and used for testing external response information of the multi-rotor unmanned aerial vehicle; the calculation processing center comprises a data collecting unit and a data analyzing unit. The test platform is simple in structure, good in flexibility and capable of accurately testing multiple performance indexes of the aerial vehicle.

The invention provides an online detection method of energy consumption information in a machining process of a main drive system of a machine tool. According to the method, real-time data, such as loss power of a mainshaft motor, output power of the mainshaft motor, loss power of a mechanical drive system, cutting power, and the like of energy consumption information of the main drive system of the machine tool can be solved just by measuring the total input power of the machine tool in the production site in the machining process, according to established mathematical models of energy flowsand main energy consumption information of the main drive system in the machining process of the machine tool, and base data, such as no-load power and additional load loss coefficient of the machinetool, which are obtained in advance when a mainshaft is in a machining rotation speed, rated power of the mainshaft motor, rated efficiency of the mainshaft motor, no-load power of the mainshaft motor, and the like. The online detection method can be directly applied to researches, such as acquisition of energy efficiency of the machine tool, efficiency estimation of the machining process, energyconsumption monitoring, energy management and energy saving technologies and has wider application prospect.

The invention provides an energy consumption prediction method for use in the service process of a numerically-controlled machine tool specific to the current situation of the lack of an energy consumption prediction method for a numerically-controlled machine tool. In the method, an energy prediction model for use in the service process of a numerically-controlled machine tool based on energy prediction of three types of sub-processes such as starting, idle load and processing on the basis of energy consumption characteristic analysis for the service process of the numerically-controlled machine tool. The energy prediction model for every type of sub-process is resolved respectively, so that an energy consumption prediction result of an entire numerically-controlled machine tool service process is obtained. According to the method, the energy consumption of a machine tool processing process can be predicted directly according to numerical control processing technic parameters.

The invention provides a voltage control method of a Y-type connected direct-current bus of a serially-connected H bridge multi-level grid-connected inverter, which controls the whole serially-connected H bridge multi-level grid-connected inverter to absorb active power from a power grid, so as to realize stable total direct-current bus voltage of three phases. Needed zero sequence voltage is synthesized by a Y-type topological structure through detection and calculation so as to adjust balance between every two phases of direct-current buses; module instruction voltage between every two phases is finely tuned and the active power adsorbed by each module is redistributed, so that the active power which is actually adsorbed by the module can cancel the loss of the module; and therefore, each module can be stably operated under the rated instruction voltage value.

The invention discloses a voltage-sharing controlling method for a direct current bus voltage of a single-phase power electronic transformer. A power main circuit of a single-phase DC-AC power electronic transformer is composed of an isolation level and an inversion level. The isolation level comprises high frequency isolation type DC-DC convertors. The inversion level comprises DC-AC inverters. The input ends of all the DC-DC convertors of the isolation level are in series connection with a medium voltage or high voltage direct current voltage source. The output ends of the DC-DC convertors are connected with the direct current input ends of the corresponding DC-AC inverters of the inversion level. The alternating current sides of all the DC-AC inverters of the inversion level are in series connection with an output filter. The controlling method comprises the following steps: firstly, the voltage-sharing control is carried out on bus voltages of the direct current source side of the power electronic transformer; secondly, the voltage-sharing control is carried out on bus voltages of the output side of the isolation level of the power electronic transformer. According to the controlling method, the voltage-sharing control among cascading modules of the cascading type single-phase power electronic transformer can be achieved, and the method is simple. The correctness and the reliability of the method are verified through simulation results, and a good reference value is provided for the engineering application.

The invention provides a construction method for a shallow-buried large-span small-spacing loess tunnel in order to resolve the problems that an existing large-section small-spacing loess tunnel is high in construction difficulty and high in danger coefficient, and sedimentation is difficult to control. According to the method, two holes of the tunnel are constructed at the same time, and each hole is divided into two guide holes for construction. An annular surface formed by sealing the distance between a face of a later passing hole and an inverted arch of a former passing hole is one time diameter of each hole. Each hole is divided into the left guide hole and the right guide hole, wherein the guide hole at the side far away from a soiled-clamped pillar is firstly excavated, the interval between faces of the two guide holes keeps 5-8m, the guide hole at each side is excavated through three steps of an upper step, a middle step and a lower step, and interval between the steps keeps 3-5m. Compared with a similar excavation technique for the tunnel, the construction method effectively guarantees safe construction of the tunnel, reasonably controls the sediment of the tunnel, reduces the influence on the ground surface from construction, and improves the construction efficiency to some extent.

The invention provides a hemoglobin, hemoglobin-haptoglobin composite and transferrin joint examination kit. The hemoglobin, hemoglobin-haptoglobin composite and transferrin joint examination kit comprises an upper shell, a lower shell, an immunostrip, test paper and the like; a gold-labeled composite containing a hemoglobin monoclonal antibody, a hemoglobin-haptoglobin composite monoclonal antibody and a transferrin monoclonal antibody is scribed on a nitrocellulose membrane; 3 test lines, a quality control line (15) and a gold-labeled composite membrane scribing line (8) are arranged on the nitrocellulose membrane in parallel. The invention further provides a preparation method and a detection method of the hemoglobin, hemoglobin-haptoglobin composite and transferrin joint examination kit. The hemoglobin, hemoglobin-haptoglobin composite and transferrin joint examination kit is convenient and simple in operation, stable in performance and accurate in result, has a relatively good reference value for early diagnosis and identification of colorectal cancer or colon cancer tumor or other tumors with lower gastrointestinal bleeding symptoms in clinic, significantly improves the positive detection rate of digestive hemorrhagic diseases, is suitable for clinical hospital examination and household self-examination, and provides measures for large-scale general examination of such diseases.

The invention discloses a sliding-mode variable structure control method of a single phase grid-connected inverter based on a multi-resonant sliding mode surface. The method comprises the steps of: firstly, building a linear sliding mode surface according to detected current i1 of an inverter side filter inductor of the single phase grid-connected inverter, the voltage vc of a filter capacitor, the current i2 of a network side filter inductor, and the target output current i1* of a grid-connected inverter system, the target voltage vC* of the filter capacitor and the grid-connected target current i2*; adding a resonant item into the linear sliding mode surface so as to obtain the multi-resonant sliding mode surface; designing a sliding-mode variable structure controller by the multi-resonant sliding mode surface, leading a linear state feedback controller to an original nonlinear controller to obtain a final control quantity modulation wave d(s), and finally comparing the modulation wave with a carrier wave to generate a driving signal for driving a switch tube to act. According to the control method disclosed by the invention, the robustness and dynamic response ability of the grid-connected inverter system are improved; the tracking accuracy of grid-connected current is also improved; the harmonic content is removed, and the control method is simple and easy to achieve.

The invention discloses a transcript number dynamic adjustment method based on file heat and node load. The method comprises the following steps: 1) setting reliability parameters according to file reliability, and initializing the transcript number of the file; 2) performing statistics on the access times, and calculating the file heat hoti; 3) calculating an average access heat havg of the file,and dividing files in a set F into hotspot files, ordinary files and cold files; 4) calculating the average node Lavg of nodes, and dividing the nodes into heavy load nodes, intermediate load nodes and light load nodes; and 5) traversing the files in the set F I, calculating a theoretical transcript number Mi of the file according to the file heat and the node load, and dynamically adjusting thetranscript number rm of the file. According to the method, the current access amount and the previous file heat are counted, the influence of the file change rate to the heat is considered, the transcript number is dynamically adjusted via the average access heat of the files and the average load of the nodes in the cluster, thereby reducing the average response time and improving the overall performance of the cluster.

The invention discloses a VMD-GRU-based short-term wind speed prediction method. The method is characterized is characterized in that it comprises, acquiring data of wind speeds at the current momentand n moments closest to the current moment to form a time sequence; and preprocessing the time sequence to obtain a plurality of sub-sequences and residual components, respectively inputting each sub-sequence and each residual component into respective corresponding trained GRU models, outputting predicted values by the trained GRU models, and performing post-processing on all the predicted values to obtain future wind speed prediction data at the next moment. According to the method, non-stationary wind speed data is decomposed into sub-sequences and residual components with different frequencies by adopting a variational mode decomposition method, the stability of the sub-sequences and the residual components is good, and better prediction is facilitated; the method has good predictionprecision for the wind speed with strong volatility, randomness and uncertainty, and the operation state of the wind power generation device can be adjusted more reasonably.

The invention belongs to the technical field of teaching quality evaluation and application, and discloses an online course video resource content identification and evaluation method and an intelligent system. The method comprises the steps of obtaining a target online course video, and obtaining video stream information and audio stream information from a video file; processing the video streaminformation to obtain shot extraction and image texts, and performing audio fragment segmentation and voice recognition on the audio stream information to obtain voice texts; carrying out knowledge point identification on the content of the video resource according to the image text and the voice text; and comparing the video knowledge points with the course outline, and evaluating and auditing the teaching content. According to the invention, quality evaluation and auditing can be carried out on the online course teaching video from multiple angles, the evaluation result is based on the image, voice and specific course content of the video, the teaching content of the online course teaching video can be comprehensively analyzed and evaluated, and the invention has great reference value and practical significance for an online course platform and a producer.

The invention relates to a transparent soil model pile experimental testing device and an application method thereof. The whole system comprises an experiment table and a model experiment device, wherein the experiment table can be leveled through setting adjustable table legs; a desktop is provided with a bracket and a bracket fixing plate so as to mount an engineering diffuser, a camera and a laser device, and is provided with a slide model fixing plate and a vertical and transverse slide limiting plate so as to position and fix a model testing groove; a counter-force frame is arranged above the model testing groove, is adjusted by an adjustable type screw rod and a fixed screw cap and is fixedly arranged on the tabletop; the counter-force frame is provided with a small-size hydraulic jack and a pressure meter; artificially synthesized transparent soil is arranged in the model testing groove and the model testing groove is provided with a model pile and a model pile loading head so as to carry out a post-period model test. The whole system is reasonably arranged, and a loading test and observation on displacement and deformation conditions can be conveniently carried out on the model pile in the artificially synthesized transparent soil.

The invention provides an accuracy control method for single-phase diode clamping three level midpoint potential imbalance, which specially aims at the accuracy control of the midpoint potential imbalance by analyzing the influence of the zero level to the direct current-side midpoint potential, and changing the distribution of the zero level among different bridge arms due to the symmetry and the redundancy under the condition that the outlet voltage wave form is not changed and the direct current component is not led, wherein the control method is only relevant to the modulating wave of each module, and is suitable for a large-scale cascade diode clamping topological structure. According to the method, the modulating wave of each module is divided into two parts, the two modulating waves are equal in size and reversed in directions and respectively control the left half bridge and the right half bridge of the diode clamping, and the required direct current component is injected into the modulating wave as required, so that the accuracy control of the midpoint potential can be formed, and additional auxiliary devices are not needed, therefore, the method is simple and easy. The simulation and experiment results show the exactness and the reliability of the method, so that a good reference value can be provided for the engineering application.

A non-volatile semiconductor memory device is provided comprising a memory area and a circuitry area. The memory area includes a plurality of memory cells and a set of array reference cells that are programmable to have a threshold voltage corresponding to an erased or a programmed state of a memory cell. In the circuitry area, additional main reference cells are provided, which are configured to also have a threshold voltage corresponding to an erased or programmed state of a memory cell. The main reference cells are used for setting of said array reference cells and said array reference cells are provided as a reference for reading or writing a state of said memory cells. A method is also provided for setting array reference cells in a non-volatile semiconductor memory device to a predefined threshold voltage.

The invention relates to a method for extracting and identifying graphic and text information of a scanned document, which comprises the following steps of: 1) preprocessing a scanned document image,carrying out layout segmentation on the preprocessed image, and selecting items, including but not limited to, a signature and a seal; (2) preprocessing the signature extracted in the step (1), removing a background by adopting an OTSU algorithm, inputting the signature into a Writer-Dependent network to extract a characteristic value of the signature, and inputting the characteristic value into an SVM classifier obtained by using real signature training to obtain the authenticity of the signature; (3) conducting polar coordinate transformation on the seal extracted in the step (1) after preprocessing, so that annular characters in the seal are expanded into transversely-arranged characters, inputting the expanded characters into a CPTN + CRNN network to be sequentially extracted and recognized, and outputting the character content of the seal; 4) judging the validity of the document. The method can replace manual work to analyze and judge the document.

The invention discloses a deep-sea working ROV (Remotely Operated Vehicle) propeller system. An ROV controller can generate a speed control instruction of six degrees of freedom according to the current motion state of an ROV; a communication unit adopts a TCP (Transmission Control Protocol)/IP (Internet Protocol) network communication mode and transmits the speed control instruction generated by the ROV controller to a thrust distribution unit; a propeller unit comprises four horizontal propellers and three vertical propellers; the thrust distribution unit decomposes the instruction according to the received speed control instruction, and the obtained thrust values of all the propellers are transmitted to a driving unit; the driving unit outputs corresponding voltage signals according to the received thrust values and transmits the voltage signals to a propeller proportional valve, and opening and closing of the propeller proportional valve is adjusted; a hydraulic unit transmits hydraulic oil to the propeller unit through the propeller proportional valve. The deep-sea working ROV propeller system can improve the execution capability and efficiency of a propelling system.

The invention discloses a control method of a modular multilevel converter based on a power frequency fixed switching frequency. The control method includes the steps that the modulation strategy that impulse waveforms are moved periodically is adopted, so that the characteristics of four impulse waveform parameters in one group are determined; specific values of the impulse waveform parameters are determined by referring to the latest level modulation strategy, fine adjustment is conducted on the impulse waveform parameters by the utilization of an impulse waveform parameter vector mode and according to an active energy equipartition principle, an impulse waveform parameter table is compiled, and under the condition that the total distortion rate of voltage harmonic is guaranteed, and automatic balancing of module absorbing power is achieved. A modulation ratio is determined by detecting the actual value of a power grid voltage and the actual value of a power grid current, the table is looked up according to the modulation ratio to obtain the impulse waveform parameters, then the impulse waveforms are moved periodically according to the corresponding principle and the number of sub-module cascades to obtain sub-module switching signals when capacitor voltage control does not exist, the control over the modular multilevel converter based on the power frequency fixed switching frequency is realized, and good reference value is provided for engineering application.

The invention discloses a method of building a reliable improved effect relation between investment on a power grid and power supply. Firstly, a relation model of feeder improvement measure investment and reliable improved effects (for reducing household weigh at blackout) including annular grid improvement, segment switch increasing, superterranean moved cables and the like is built with feeders serving as units. A cost and benefit analyzing method is used for estimating all effects of improvement measures and finally, a reliable relation model of the investment on the power grid and power supply is set up. With the method of building the reliable improved effect relation between the investment on the power grid and power supply, parameter variation of a feeder grid frame and improved household number in blackout corresponding to reliable parameter variation can be rapidly and effectively estimated, a good indicating effect can be exerted on a reliable improvement scheme on the power grid, a complicated power grid reliability estimating process is avoided, excellent reference values can be provided for arrangement of improvement of the power grid in a macroscopic mode and obtaining of the reliable level of the most proper power grid.

The invention discloses a management system of community resident health information. The management system comprises a basic information module, a health current situation module, a physical examination information module, a historical case history module, a health maintenance module, a genetic disease history module and a health early warning module, wherein the basic information module is used for recording the basic information and the account password of a resident; the health current situation module is used for recording the living habit, the diet habit and the life pressure information of the resident, and establishing keyword retrieval; the physical examination information module is used for looking up the physical examination information of the resident and establishing the keyword retrieval for key information; the historical case history module is used for storing the historical hospitalizing and doctor seeing information of the resident; the health maintenance module is used for storing health maintenance information and the health standard information of each physical examination item; the genetic disease history module is used for storing family genetic disease history situation information; and the health early warning module is used for comparing the physical examination information in the physical examination information module with the health standard of each physical examination item of the health maintenance module, and carries out a health early warning when a set threshold value is reached, and a community manager updates an early warning index threshold value in real time. The management system has the advantages of being low in cost and easy in maintenance, can find the health situation of the resident in time and can prompt the resident to see a doctor in time.

The invention provides a control method for online dynamically restraining power grid low frequency oscillation and subsynchronous oscillation. Firstly, power grid voltage and current are acquired via a sensor, and after the voltage and the current are converted into signals readable by a digital processor, online real-time quick FFT is carried out via a digital signal processor (DSP); then, an SVG current control strategy is designed, and the SVG outputs accurate reactive power compensation according to a real-time power grid low frequency oscillation component and a subsynchronous oscillation component. On the basis of the original SVG control strategy, control algorithm for online dynamically restraining power grid subsynchronous oscillation is added, positive damping can be effectively provided with a wind farm, and a wind power generation system is stabilized; and compared with the existing restraining strategy, the SVG can output more accurate and quicker active power and reactive power according to the real-time power grid subsynchronous oscillation component, and the subsynchronous oscillation problem in the power grid is solved.