34results about How to "Reduce calculation errors" patented technology

The application is suitable for the technical field of unmanned ship, and provides an unmanned ship mapping method, an unmanned ship and a computer readable storage medium, which comprises the following steps: in the process of unmanned ship sailing, a plurality of first position points in a target environment where the unmanned ship is located are acquired by a monocular vision device of the unmanned ship; for any one of the first position points, a bearing angle sequence of the unmanned ship relative to the first position point is acquired by the monocular vision device; positioning information of the first position point is calculated according to the bearing angle sequence; and a map of the target environment is generated according to the positioning information of each first position point in the target environment. Through the above method, the problem that the unmanned ship cannot accurately map due to limited load can be solved.

The application relates to the technical field of nuclear power plant safety testing, and particularly relates to a method for calculating the value of a control rod by a falling rod method and a device and an electronic device thereof, which comprises the following steps: acquiring the initial time t0 of a to-be-tested control rod before falling rod starts, the neutron flux density n0 corresponding to the initial time t0, the time t1 of falling rod ending, the neutron flux density n1 corresponding to the time t1, and the second neutron flux density n2 corresponding to any time t2 after the falling rod ends; calculating the period T1 of the time after the falling rod; and calculating the value |p1| of the to-be-tested control rod. In the application, the optimized formula simultaneously considers the influence of prompt neutrons and delayed neutrons, so that the measurement error of the falling rod method can be significantly reduced.

The application provides an evaluation device and method for phase measurement error of a spherical near-field antenna when the antenna is installed eccentrically, which can evaluate the phase measurement error of a to-be-measured antenna in a certain direction, a certain section and a certain angle range of a space under different eccentric distances of the antenna in a field. The device comprises a spherical near-field scanning ring 7, a low-frequency probe array 8, a high-frequency probe array 9, a spherical near-field test azimuth turntable 11 and an adapter tool 12. The two half rings of the spherical near-field scanning ring 7 are respectively arranged with the low-frequency probe array 8 and the high-frequency probe array 9. The spherical near-field test azimuth turntable 11 is located on the central axis of the spherical near-field scanning ring. The azimuth turntable 11 is connected with the adapter tool 12. The tool main body structure 1 and the counterweight 6 are connected with the turntable flange 3 and are installed on the adapter tool 12. The to-be-measured antenna 10 is installed on the antenna installation hole 2 of the test tool.

The application discloses a kind of based on time-sharing user's rate time period exception checking method, equipment and medium, the method includes obtaining user rate time period agreement parameter and user profile information from marketing system, obtains electric meter rate time period parameter measurement data from metering automation system, daily frozen electric quantity data and load curve data, and data preprocessing is carried out to the data collected;Parameter checking matrix P and electric quantity checking matrix E are constructed;According to the preset timing trigger condition and event trigger parameter exception checking and electric quantity exception checking;According to the checking result, divide exception type, and carry out visual display;According to exception type, generate processing work order and push to operation and maintenance end, update parameter checking matrix P and electric quantity checking matrix E after processing result feedback, complete exception closed-loop management.The application effectively solves the problems of insufficient parameter measurement accuracy, single electric quantity checking dimension, missing dynamic checking mechanism and low efficiency of exception positioning in the prior art.

This invention relates to a target localization and counting method based on point domain feature learning. The method includes: inputting the image to be detected into a backbone network to extract a three-level feature pyramid comprising top-level features, intermediate-level features, and bottom-level features; inputting the three-level feature pyramid into a multilayer perceptron module to capture the global long-distance dependence of its top-level features and obtain global information features; inputting the three-level feature pyramid into a visual centering mechanism module to aggregate local region features of its top-level features, obtain local information features, and connect them with global information features along the channel dimension to obtain mapped top-level features; then, combining these with intermediate-level and bottom-level features to form a mapped three-level feature pyramid; inputting this pyramid into a global centralization adjustment module; outputting an initial feature map to a multi-perceptron module; extracting channel features and spatial features and concatenating them to obtain a multi-perceptron feature map; then, passing through a regression head to output the predicted target count of the image to be detected; and finally, passing through a classification head to output the predicted target localization of the image to be detected.

The application discloses an eye diagram data synchronization circuit and method and a serial-parallel converter receiving end, and belongs to the technical field of high-speed serial data communication; the circuit comprises: a calibration signal generation module for generating a phase calibration signal according to a phase difference between a data sampling signal and an offset sampling signal; two registers for respectively outputting the offset sampling signal and pre / post offset sampling signals; wherein the pre / post offset sampling signals are obtained by outputting the offset sampling signal in advance / delaying half a bit period; and a selection output module for selecting the offset sampling signal or the pre / post offset sampling signals as a synchronized offset sampling signal output according to the phase calibration signal, so that the synchronized offset sampling signal and the data sampling signal are in the same bit period. The application has wide application range, high synchronization precision and good dynamic performance.

This invention relates to a reversible and reapplicable land parcel mapping method, comprising: loading target land parcel data; binding a map canvas; establishing map event listening and location status reception; determining the point type, status, and region component corresponding to the current operation; constructing a corresponding edit command object; executing the edit command object to generate modified data; writing the executed reversible edit command object into a reversal history queue, and maintaining the reversal history queue and the reapply queue; and extracting the target edit command object to realize the reversal or reapply of the land parcel mapping results. The reversible and reapplicable land parcel mapping method designed using this invention can solve the problems of existing map mapping processing, such as lack of stable operation rollback capabilities, high maintenance difficulty, easy occurrence of untraceable operations, difficulty in state recovery, and unstable maintenance of historical records.

The invention belongs to the technical field of force sensors, and provides an anti-unbalance-loading multi-dimensional box-type force sensor, which comprises a sensor elastic body, a first surface and a second surface are arranged on the sensor elastic body, four groups of strain gauges are arranged on each of the first surface and the second surface, each group of strain gauges comprises three strain gauges, and the number of the strain gauges is two. The 24 strain gauges form four groups of Wheatstone bridges which are respectively used for measuring shearing force, bending force and torsional force. The upper surface and the lower surface for accommodating the symmetrically distributed strain gauges are arranged on the elastic body through the sensor, the shearing force, the bending force and the torsion force are respectively measured by combining four groups of Wheatstone bridges, multi-channel signals are subjected to fusion calculation through a least square decoupling algorithm, and finally, synchronous and accurate measurement of the load weight and the position on the working platform is realized. The weight calculation error is reduced to the minimum, the load position can be accurately locked, and the measurement deviation caused by different weight positions is eliminated.

The application discloses a kind of urban rainstorm waterlogging multi-source pollution tracing methods based on two-way dynamic coupling, first, the acquisition of multi-source data is carried out, then two-dimensional shallow water equation solver ANUGA calculation domain is constructed and initialized, that is, the initialization of surface water dynamic model is completed, then two-way dynamic coupling model of surface and pipe network is constructed;Subsequently, water quality transport analysis is carried out, and by building a pollution source fingerprint library, the qualitative identification and quantitative tracing analysis of pollution source are completed based on multi-pollution source water quality tracing model.The application realizes the whole-chain integrated simulation and analysis of surface water dynamics, drainage pipe network hydraulics, water quality transport and pollution tracing, solves the problems of model decoupling, water quality dimension loss, imperfect tracing method and lack of systematic tracing framework, and meets the engineering needs of high-precision, real-time sewage tracing under urban rainstorm waterlogging scenario.

The application discloses a kind of based on intravascular imaging optimization three-dimensional vascular model interframe interpolation method;Obtain the sequence image group collected by intravascular imaging technology;And each frame image in sequence image group is carried out denoising processing;Using segmentation algorithm extracts the lumen boundary in each frame image, obtains the two-dimensional profile sequence image group of vascular lumen with frame data;Interpolation times are calculated;According to interpolation times, difference image group is generated, and according to the frame data of each image in difference image group, it is inserted into two-dimensional profile sequence image group;According to the last obtained two-dimensional profile sequence image group, generate high-resolution three-dimensional vascular model.The application is obtained by the frame interpolation technology of image collected by intravascular imaging technology, and the frame distance of adjacent image is reduced, and the continuity and smoothness of three-dimensional vascular model are improved.

The utility model discloses an anti-falling grain pile height gauge, and particularly relates to the technical field of grain pile detection machinery. Comprising a head height measuring rod and a body height measuring rod which can be connected into a whole, the head height measuring rod is a hollow pipe comprising a tip section and a connecting section, the body height measuring rod is a hollow pipe comprising an inserting section and a connecting section, the outer diameter of the inserting section is the same as the inner diameter of the connecting section, and the inserting section extends into the connecting section to connect the head height measuring rod and the body height measuring rod; the inner side of the head height measuring rod is fixedly connected with a head anti-disengaging ring, the head anti-disengaging ring is connected with a head anti-disengaging rope, and the head anti-disengaging rope penetrates through the inner side of the head height measuring rod and the inner side of the body height measuring rod and extends out of the connecting section. According to the height measuring device, the head anti-falling ring and the head anti-falling rope are arranged, the head height measuring rod and the body height measuring rod are connected, the problem that parts of the height measuring device are lost due to falling of the rods of the height measuring device is solved, the efficiency of measuring work is improved, and unnecessary disturbance to grain piles and influence on the stability of grain storage are avoided.

The invention discloses a main transformer differential protection automatic calculation method and system, and belongs to the technical field of power system relay protection. Traditional main transformer differential protection calculation depends on manpower, is high in complexity, is easily influenced by parameter errors and is low in efficiency. Multi-source parameters such as a main transformer nameplate parameter, a CT / PT transformation ratio and a winding wiring mode are automatically acquired and verified through the parameter analysis module; self-adaptively calculating the balance coefficient of each side by using a dynamic balance coefficient calculation algorithm; a phase compensation matrix is automatically generated based on the wiring mode, and compensation effect verification is carried out; characteristic inflection points of the proportional braking characteristic curve are automatically searched through a six-phase current synchronous injection method, and an optimized proportional braking characteristic curve is generated through a curve fitting algorithm; and finally, carrying out optimization recommendation and dynamic adjustment on the differential fixed value by means of an AI auxiliary decision-making module. According to the method, full-process automation from parameter input to constant value generation is realized, the calculation efficiency and precision are remarkably improved, and rapid and accurate setting calculation support is provided for differential protection of the main transformer.

This application belongs to the field of cloud measurement technology, specifically relating to a method and system for cloud area identification and cloud cover calculation based on an all-sky imager. The method selects a normalized difference processing method to identify cloud areas, and introduces a brightness threshold for sky images with strong sunlight that are not completely covered by clouds. An initial threshold is selected based on the maximum inter-class variance (MOV) method, and then the brightness threshold is further selected using MOV for the sky images with the introduced brightness threshold. Preliminary cloud area identification is performed on the all-sky image using the initial threshold, and then the threshold is adjusted based on image features to achieve cloud area identification. Morphological smoothing is applied to the sky image after cloud area identification. Geometric correction is then performed on the smoothed image to calculate cloud cover. The advantages of this invention are that it utilizes differentiated processing of sky images, introduces a brightness threshold for cloud areas with strong light interference, combines morphological smoothing to reduce noise impact, effectively improves the accuracy of cloud area identification, and finally reduces cloud cover calculation errors through geometric correction.

The invention discloses a low-drift phase change memory array, architecture and neural network operation component, the phase change memory array is composed of m rows and k columns of phase change memory units, top electrodes of phase change elements in the phase change memory units are electrically connected with drain electrodes of switch elements, bottom electrodes of the phase change elements in the phase change memory units are connected with bit lines, grid electrodes of the switch elements are connected with word lines, the source electrode is connected with the source line; the phase change memory architecture comprises a control circuit, a word line (WL) driver, a bit line (BL) driver, a source line (SL) driver, an input or output processing circuit and a phase change memory array, the neural network operation assembly comprises a phase change memory array, an input circuit, a driving circuit, a programming circuit, an output circuit and a digital processing circuit. According to the invention, the resistance drift phenomenon of each storage unit in the device array is effectively inhibited.

The invention relates to the technical field of emolument management, in particular to a configuration-based installation and maintenance emolument management method and system, and the method comprises the following steps: configuring emolument parameters and auditing rules, dynamically calculating emolument, storing emolument data and auditing records, and carrying out user interaction. The method has the beneficial effects that the transparency of salary management is improved, so that employees can clearly know own salary composition and change conditions. The emolument calculation process is simplified, calculation errors are reduced, and the management efficiency is improved. The flexibility of salary management is improved, and enterprises can quickly respond to market changes and adjust salary strategies. Finally, the effects are helpful for improving the satisfaction degree of employees and the operation efficiency of enterprises and promoting the sustainable development of the enterprises.

The application discloses a magnetic levitation train brake control method and device and a computer readable medium, wherein the method comprises the following steps: acquiring an excitation current of an eddy current brake electromagnet and a running speed of the magnetic levitation train; determining an electromagnetic gap between the eddy current brake electromagnet and a lateral track according to the excitation current and the running speed; determining an eddy current brake force generated by the eddy current brake electromagnet and a wear plate friction force between a wear plate of the eddy current brake electromagnet and the lateral track according to the excitation current, the running speed and the electromagnetic gap; determining a skid friction force between a skid and the track according to the running speed; determining a train brake force according to the eddy current brake force, the wear plate friction force and the skid friction force, and performing brake control on the magnetic levitation train according to the train brake force. The application determines the brake force of the magnetic levitation train by combining the influence of the dynamic electromagnetic gap on the brake force, is more in line with the actual situation of train braking, effectively reduces the calculation error of the train brake force, and accordingly improves the accuracy of the train brake control.

The invention relates to the technical field of remote sensing monitoring, in particular to an under-construction bridge temperature inversion method and system based on unmanned aerial vehicle thermal infrared remote sensing. The method comprises the following steps: determining an adaptive unmanned aerial vehicle platform according to structural parameters of a bridge under construction, geographical conditions of a monitoring area and an operation endurance demand, carrying a color CCD camera and a common digital camera to form a dual-camera load, and completing synchronous calibration of an unmanned aerial vehicle inertial measurement unit, a global positioning system module and the dual cameras; through complementation of functions and characteristics of the double cameras, system errors of radiation brightness detection are reduced from a data source, a color CCD camera provides stable basic radiation data, a common digital camera supplements effective signals under extreme conditions, and time-space coordinates are ensured to be consistent through synchronous calibration. Radiation brightness acquisition deviation caused by performance limitation of a single camera is avoided, the stability of radiation brightness detection is improved by more than 30%, and more reliable basic data are provided for subsequent temperature inversion.

The present disclosure relates to an energy recovery method, device, storage medium and vehicle, which is applied to a pure electric vehicle, can improve the accuracy of slope estimation in the energy recovery strategy, thereby improving the energy utilization rate of the vehicle, and guaranteeing the braking safety and driving comfort of the vehicle. The energy recovery method comprises the following steps: obtaining a first slope value of a position where a vehicle is located from a gyroscope; obtaining a second slope value of the position where the vehicle is located and a third slope value of a road section in front of the vehicle from a high-precision map module; when the driving road condition of the vehicle is a slope road condition, determining a target slope value of the position where the vehicle is located according to the first slope value, the second slope value and the third slope value; and performing energy recovery on the vehicle according to the target slope value.

This invention discloses a test method for determining the plastic strain ratio. By introducing the concept of a finite body and specifying the consistency of the measurement point positions before and after deformation, and using conventional measuring tools and different test conditions, the plastic strain ratio is determined, ensuring the stability of the data measurement results, improving test efficiency and reliability, and eliminating the problem of large fluctuations in the r-value measurement results caused by many uncontrollable factors in existing standards. It achieves accurate determination of the r-value in a low-cost, simple, and efficient manner. Therefore, this invention has important engineering practical significance and broad engineering application prospects.

The embodiment of the application discloses a kind of parameter calculation methods under asymmetric short-circuit fault condition. Among them, the method comprises: under symmetric short-circuit fault condition, obtaining the expected current ac component oscillogram of symmetric short-circuit;By expected current ac component oscillogram, the current effective value and the phase angle difference of current voltage of multiple time are measured;Under asymmetric short-circuit fault condition, the voltage phase angle of multiple time is measured;According to current effective value, the phase angle difference of current voltage and voltage phase angle, attenuation coefficient is calculated;According to attenuation coefficient, direct current time constant is calculated;According to current effective value, the phase angle difference of current voltage, voltage phase angle and the direct current time constant determine asymmetric short-circuit current expression, so current expression under asymmetric short-circuit fault condition can be simply and accurately obtained, and the operation amount and error rate are reduced.

This application relates to the field of intelligent video surveillance technology, and particularly to a camera calibration and camera target detection and localization method, apparatus, and electronic device. The method includes: acquiring a first set of image coordinates and timestamps of a target device acquired by one or more cameras, and acquiring a second set of the position and timestamps of the target device itself in a 3D map; identifying the world coordinate set in the second set corresponding to the image coordinate set in the first set at any timestamp; calculating a coordinate transformation matrix between the image coordinates and world coordinates of each camera based on the image coordinate set and the world coordinate set; using the coordinate transformation matrix to determine the positional mapping relationship of the target device between the world coordinate system and the image coordinate system, and calibrating the parameters of the corresponding camera to obtain the camera calibration result. This solves the problems of low accuracy of camera intrinsic parameters calculated by related technologies and limitations such as applicability only to indoor scenes.

The utility model relates to natural gas scheduling technical field provides a kind of system for natural gas scheduling operation, comprising: data acquisition module, including multiple field devices and third party equipment, gather natural gas process operation equipment state information;Communication server is connected with data acquisition module, receives the data information collected by data acquisition module and uploads to control center;The control center includes data monitoring switch, database server and station operating station, real-time monitoring and store the collected data;The database server is connected with data monitoring switch, and the station operating station is connected with communication server, and the communication server is connected with data monitoring switch;Data unified inquiry platform is connected with control center, and real-time required data is obtained.The utility model solves the problem that each item of material in the process of natural gas scheduling operation is more complex, and the safety is lower.

The invention discloses a shield construction overexcavation amount early warning method and early warning device, belongs to the technical field of tunnel construction, and aims to overcome the defects that in the prior art, overexcavation amount calculation is inaccurate, parameters are difficult to obtain due to dependence, early warning is not associated with actual risks, and man-machine interaction is insufficient. According to the method, shield tunneling ring footage is used as a calculation unit, the theoretical slag discharge amount is calculated by introducing a soil body loose coefficient, the actually measured slag discharge amount is obtained by adopting contour collection and belt speed monitoring, and the actual over-excavation amount is obtained by deducting the injection amount; and based on equivalent stratum loss or a settling tank theory, the over-excavation amount is converted into the maximum settlement amount of the earth surface, and a two-stage grading early warning mechanism is established. The device comprises a data acquisition module, a data communication module and a man-machine interaction module, and realizes accurate data acquisition, stable transmission and intelligent early warning. According to the method, the over-excavation amount calculation precision is improved, the relevance between early warning and engineering risks is enhanced, man-machine interaction is convenient, and the shield construction safety management and control level can be remarkably improved.

The invention discloses a method for calculating the contact stiffness of a planetary roller screw under mixed lubrication, and belongs to the field of planetary roller screw transmission. The method comprises the steps that on the basis of a planetary roller screw mixed lubrication contact interface model, the rough contact load of a thread tooth is calculated through a GW model, the oil film contact load is solved through a central film thickness dimensionless equation, the oil film thickness, the rough contact load and the oil film load are solved at the same time, and according to the solved rough contact load, the rough contact load of the thread tooth is calculated. And solving the rough contact rigidity of the planetary roller screw under mixed lubrication by using a WAO model, and solving the oil film rigidity of the planetary roller screw under mixed lubrication by using the oil film thickness and the bulk modulus, so that a contact model of the planetary roller screw under mixed lubrication can be obtained. According to the method, the blank of a planetary roller screw contact stiffness model under mixed lubrication is filled up, and the influence of factors such as the axial load, the surface roughness and the lubricant viscosity of the planetary roller screw on the mixed lubrication contact stiffness can be directly solved.

The utility model provides a kind of dissimilar steel laser welding residual stress testing device, comprising: pedestal platform, three-axis movement module, drilling unit, strain measurement module and data processing unit;Pedestal platform uses aluminium alloy frame, built-in horizontal adjusting mechanism, three-axis movement module is driven by stepper motor, precision ±0.01mm, realize measuring point accurate positioning, drilling unit integrates high-precision electric spindle (rotating speed 0-10,000rpm adjustable), is equipped with diameter 2mm hard alloy drill bit, drilling depth is controlled in real time by laser displacement sensor, strain measurement module includes BE120-2CA type three-way strain flower and static resistance strain gauge, strain release data (epsilon 0, epsilon 45 , epsilon 90 ) after drilling are collected in real time, data processing unit is built-in embedded system, residual stress (sigma x , sigma γ ) is automatically calculated and generates stress distribution nephogram, by automation drilling and strain acquisition technology, the quick, high-precision measurement of residual stress of welded joint is realized, suitable for the quality evaluation and process optimization of dissimilar steel weld.

The invention relates to a method for predicting the thermal resistance of a groove type heat pipe, which comprises the following steps of: equally dividing the groove type heat pipe into a plurality of same independent groove units according to the number of grooves on the section of the groove type heat pipe, acquiring calculation parameters of each independent groove unit, and calculating to obtain the liquid filling rate of the groove type heat pipe, the initial effective liquid level height of each independent groove unit is determined by combining the initially set heat insulation section gaseous working medium temperature and the corresponding saturated steam density, the heat flux borne by each independent groove unit is determined by combining the heat power requirement corresponding to the heating section temperature, and a partial thermal resistance network model of the axial heating section, the heat insulation section and the condensation section is established; in combination with the temperature difference constraint of the temperature of a heating section and the temperature of a cooling section, the steam flow characteristic reflected by the volume of a vaporizing medium and the influence of the length of a heat insulation section on a steam flow path, a heat resistance network model of the groove type heat pipe is constructed, and the theoretical heat transfer heat resistance of the groove type heat pipe can be calculated under the non-saturated liquid rate condition. And accurate prediction of the heat transfer resistance of the groove type heat pipe with the unsaturated liquid filling rate is realized.

The application relates to a security evaluation method and device of a digital power grid, computer equipment, a readable storage medium and a program product. Based on security indexes of digital power grid assets, a multi-dimensional asset feature vector is constructed, and based on attribute information of a current attack event suffered by the digital power grid assets, an attack feature vector is constructed; the security indexes include at least one of a port exposure index, a patch gap index and a security permission index; based on the multi-dimensional asset feature vector and the attack feature vector, a damage prediction function is constructed; the damage prediction function is used for quantifying instant damage caused by any attack to a single asset, and the output of the damage prediction function is damage intensity and a confidence interval; based on the multi-dimensional asset feature vector and the damage prediction function, a security evaluation model is constructed; and based on the security evaluation model, security evaluation is performed on the digital power grid assets. The security evaluation accuracy of the digital power grid is improved.

The present disclosure provides a calibration object having a shape substantially consistent with a scanning object of a radiation imaging device to be calibrated, and a size of the calibration object having a predetermined proportional relationship with a size of the scanning object. The present disclosure also provides a calibration system and a calibration method.

This invention discloses a method for tracing the source of multi-source pollution in urban stormwater flooding based on bidirectional dynamic coupling. First, multi-source data is acquired. Then, the computational domain of the two-dimensional shallow water equation solver ANUGA is constructed and initialized, i.e., the surface hydrodynamic model is initialized. Next, a bidirectional dynamic coupling model of the surface and the pipe network is constructed. Subsequently, water quality transport analysis is performed, and by constructing a pollution source fingerprint database, qualitative identification and quantitative source tracing analysis of pollution sources are completed based on the multi-source water quality tracing model. This invention achieves integrated simulation and analysis of the entire chain of surface hydrodynamics, drainage network hydraulics, water quality transport, and pollution source tracing, solving problems such as model decoupling, missing water quality dimensions, imperfect tracing methods, and lack of a systematic tracing framework. It meets the engineering requirements for high-precision, real-time wastewater source tracing in urban stormwater flooding scenarios.

The invention relates to the technical field of road engineering, and discloses a cold region high-grade highway recycled asphalt pavement structure optimization method which comprises the following steps: constructing an evaluation index system; the fatigue cracking life, the permanent deformation and the low-temperature crack resistance are checked in advance, when a preset threshold value requirement is met, the subjective weight of each evaluation index is determined based on row and column summation relation optimization of the preliminary matrix and a root method, and the objective weight of each evaluation index is determined according to the decision matrix and the risk correction coefficient; dynamically determining a weight fusion coefficient based on the cold region risk sensitivity index; the cold region risk sensitivity index is calculated according to an extreme low temperature coefficient and a freeze-thaw cycle coefficient; determining the comprehensive weight of each evaluation index by adopting a comprehensive weighting method; calculating the relative close degree of each recycled pavement structure scheme; and sorting the schemes according to the relative closeness to determine an optimal recycled pavement structure scheme. According to the method, the optimal recycled pavement structure suitable for the cold region can be accurately screened out.