262 results about "Stratified sampling" patented technology

The invention provides a machine vision based workpiece defect detection method. According to the method, the image of a flange type workpiece is acquired; a camera is calibrated, and calibration error is obtained; sub-pixel edge information extraction is performed on a workpiece contour; a distance from a fitting edge to the workpiece contour is calculated; whether the distance is larger than a given threshold value is judged through comparison, so that the damage condition of the workpiece contour is determined; and with the problem that the complex surface texture of the workpiece affects the segmentation of the surface scratches and corrosions of the workpiece considered, pixel stratified sampling-based PixelNet convolutional neural network is adopted to segment the surface defects. Results show that the method of the invention can accurately detect the shape defects and surface defects of the workpiece and has improved robustness.

The invention belongs to the field of milk product analysis and particularly relates to a spectral fingerprint identification method for milk, mare milk, camel milk, goat milk and buffalo milk. The invention relates to the intermediate infrared spectroscopy. The method comprises the following steps: 1) taking fresh milk, mare milk, camel milk, goat milk and buffalo milk samples; 2) scanning the samples in a mid-red spectral range to obtain mid-infrared spectral data; 3) preprocessing original mid-infrared spectrum to remove abnormal values; 4) dividing the preprocessed data set into a trainingset and a test set according to a stratified sampling principle; 5) performing dimension reduction processing on the training set to improve the model training speed; 6) establishing a model for distinguishing milk, mare milk, camel milk, goat milk and buffalo milk through 10-fold cross validation by using algorithms such as nearest neighbors on the training set, and evaluating and screening themodel by using the use accuracy, the balance precision and the Kappa coefficient; and 7) estimating the generalization performance of the optimal model.

The invention relates to multistage marine water quality stratified sampling equipment and a sampling method thereof. The multistage marine water quality stratified sampling equipment comprises a floating plate, a pay-off device and a sampling device, wherein the floating plate is of a rectangular structure, the pay-off device is installed at the upper end of the floating plate, the sampling device is arranged below the floating plate, and the sampling device is connected with the pay-off device through a steel wire rope. The problems as follows are solved: when the existing equipment is usedfor sampling the ocean water quality, the sampling effect is poor and the sampling is inaccurate, and stratified sampling cannot be effectively carried out on seawater with different depths, which isnot conducive to the study of ocean water quality; and the existing equipment cannot effectively seal the sampled seawater when sampling the ocean water quality, so that the sampled seawater is easilymixed with seawater in areas with different depths, the sample is inaccurate, and the accuracy of a water sample analysis result is influenced.

The invention provides a flight delay model establishment method and device and a prediction method and device, and relates to the technical field of machine learning, and the method comprises the specific steps: obtaining historical data, and carrying out the data preprocessing of the historical data; constructing input characteristics of a flight delay model for the historical data after data preprocessing; wherein the input characteristics comprise non-weather characteristics of the flight and weather characteristics of the flight; performing random stratified sampling on the historical data after data preprocessing to obtain a training set, a first test set and a second test set; determining a target weather feature from the weather features of the flight based on a preset algorithm; establishing a corresponding basic model according to the non-weather characteristics of the flights of the training set and the at least one target weather characteristic; over-fitting of the basic model on the training set is prevented through expression of the basic model on the first test set; and combining the plurality of basic models into a flight delay model through the second test set. Overfitting can be prevented, and an ideal prediction effect is obtained.

The invention relates to a sampling device, and in particular relates to a stratified sampling device for detecting soil. The invention aims to solve a technical problem of providing the stratified sampling device for detecting the soil, which has the advantages of simplicity in sampling operation, time saving and labor saving, high sampling efficiency, capability of taking deep-layer soil and capability of realizing stratified sampling. In order to solve the technical problems, the stratified sampling device for detecting the soil, provided by the invention, comprises a sampling box, a lower bearing block, an upper bearing block, a screw rod, a nut, a tapered block, a first sliding rail, a first sliding block, a retractable connecting rod, a shovel, a circular disc, a handle and the like; the lower bearing block is arranged in the middle of the bottom of the inside of the sampling box; the upper bearing block is arranged in the middle of the top of the inside of the sampling box; the screw rod is arranged between the lower bearing block and the upper bearing block; the screw rod stretches out of the top of the sampling box. According to the stratified sampling device for detecting the soil, manual operation is used as power, and is used for sampling the soil in different depths, so that a lot of manpower and material resources are saved to a certain extent.

The invention provides a pipe-in-pipe underground fluid stratified sampling device. The pipe-in-pipe underground fluid stratified sampling device at least comprises a pressure source, a well head fixing frame, a pipe-in-pipe underground sample introducing mechanism, a packing mechanism and a ground sampling mechanism, wherein the well head fixing frame is used for fixing the device. The pressure source provides sampling power. The pipe-in-pipe underground sample introducing mechanism is a pipe-in-pipe system and performs pipeline arrangement for underground fluid sampling. The ground sampling mechanism transmits power of a power source to the pipe-in-pipe underground sample introducing mechanism and pumps underground fluid to the ground, and then the underground fluid is collected and sampled. The gas push type sampling principle is still adopted for the device, a U-shaped pipe system is upgraded into a pipe-in-pipe system, the number of stratified sampling layers is doubled, bearing force is doubled, sampling depth is extended from a -30 m level to a -200 m level, the structure of the device is greatly simplified, stability and operability are greatly improved, and therefore the competitive advantage of the device in the field of underground fluid sampling devices is further enhanced.

The invention belongs to the technical field of underground water sampling and particularly relates to an underground water depth-setting stratified sampling device and an underground water depth-setting stratified sampling method applicable to regions without wells. The underground water depth-setting stratified sampling device at least comprises a sampling mechanism, a connecting mechanism and an underground sample injection mechanism, wherein the sampling mechanism comprises a first sampling mechanism body, a second sampling mechanism body, a sampling bottle, a gas-phase check valve, a nested flow splitting mechanism, a ball valve and a wellhead fixing support seat, the underground sample injection mechanism comprises a first underground sample injection mechanism body and a second underground sample injection mechanism body, and the connecting mechanism comprises a first connecting rod and a second connecting rod. Compared with similar technical products, the underground water depth-setting stratified sampling device applicable to the regions without the wells has the advantages that the device is novel in structural design and improved in working performance, functions, precision, stability and durability substantially, integrates a high-precision stratified sampling function and an underground water level line fluctuation monitoring function and can be rapidly mounted in the regions without the wells.

The invention relates to a stratified sampling device for water, and effectively solves the problem of tedious operation of an existing water sampling device. According to the technical scheme, the stratified sampling device comprises a ship body, wherein a rotatable piston cylinder is arranged on the ship body and wound with a water pipe, the inner end of the water pipe is communicated with the piston cylinder, and the outer end is connected with a balancing weight; a high-pressure cylinder is arranged at the upper end of the piston cylinder; a piston is arranged in the piston cylinder; a ring groove is formed in the excircle surface of the piston, an L-shaped air hole is formed in the middle of the piston, and one end of the L-shaped air hole is communicated with the ring groove; a piston rod is arranged at the lower end of the piston, a rotatable disc is arranged on the left side of the piston rod, and multiple sampling bottles are circumferentially and uniformly distributed on thedisc; a through hole is formed in the left side of the piston, a seal cover is arranged at the upper end of the through hole, a polish rod is coaxially fixed at the lower end of the piston rod, a thread is formed at the lower end of the polish rod, a ratchet and pawl structure is arranged below the polish rod, an internal thread matched with the thread on the polish rod is arranged on the inner edge surface of a ratchet, and the disc can be driven to rotate by rotation of a pawl.

The invention discloses a method for analyzing emotion polarity of long text news public opinions, which comprises the following steps: S1, collecting text data as a training sample, S2, performing data cleaning on the data of the training sample collected in the step S1, and processing special characters in the cleaned data of the training sample to obtain a data set; S3, segmenting the data set,and segmenting the training sample into a training set and a test set according to a proportion; S4, establishing a deep learning network based on the representation model and loading pre-training parameters; S5, building a long text sentiment polarity analysis network model; S6, modifying a training sample data structure; and S7, model training: adopting a stratified sampling and K-fold cross validation method to ensure that the sample proportion in the sample data set of each fold is consistent with the original data proportion during stratified sampling, storing the model result of each fold in the model with the highest score of the validation set, integrating the K-fold model to test the test set, and taking the average probability as the test result of the model.

The invention provides an in-situ stratified sampling pipe for surface sediments and a method. The in-situ stratified sampling pipe comprises a water taking pipe, a mud taking pipe, a bottom cover, a cutting head and a plurality of stratification cutting slices, wherein the bottom of the water taking pipe is connected with the mud taking pipe, and the mud taking pipe comprises a plurality of mud taking pipe components; the cross section of the inner wall of each mud taking pipe component is in a square shape, and the bottoms of three sides of the square are provided with inward arc grooves; a sealing slot is formed in the fourth side, and the bottom cover and the cutting head are detachably connected with a base at the bottom of the mud taking pipe. The in-situ stratification of sediment samples collected by the sampling pipe and the method provided by the invention can be realized. The sampling pipe and the method provided by the invention have the advantages that the structure is simple, the operation is easy, and the carrying is convenient, the sediments can be directly stratified, the sequence fidelity of the sediment samples is realized, the sampling efficiency is high, and the sampling pipe is suitable for field operation. The sampling pipe has very good practical value and broad application prospect in the technical field of ecological environmental protection.

Full-automatic aerobic composting test equipment comprises a fermentation tank, an intermittent aeration system and a control system, wherein a tail gas outlet is arranged on a fermentation tank cover, gas collection tanks are connected behind the tail gas outlet, upper, middle and lower layers of sampling and temperature ports as well as a discharge port are formed in side walls of the fermentation tank, a waste liquor outlet is arranged on the tank bottom, and a T-shaped gas distribution device is arranged in the fermentation tank; the intermittent aeration system comprises an air storage tank connected with an air pump; an air heater, a solenoid valve and a gas flowmeter are sequentially arranged on an air discharge pipeline of the air storage tank; and the control system comprises a pile temperature sensor and an environment temperature sensor which are connected to a PLC (programmable logic controller) module through a temperature module, and an output control signal of the PLC module is connected with the solenoid valve. According to the test equipment, even aeration of a pile can be guaranteed, the needed external air pressure is small, and the pile heat emission and the power consumption are less; the aeration flow, the aeration temperature, the aeration interval and the aeration duration are controlled automatically, and temperature data are recorded automatically; and stratified sampling can be performed and samples are even.

The invention discloses an in-situ stratified sampling device of soil seepage water. The in-situ stratified sampling device comprises a first-grade sampling pipe, wherein the first-grade sampling pipe is divided into a plurality of sampling chambers along the axial direction; a cone is arranged at the bottom of the sampling chamber at the bottommost part; a flow guide hole is formed in a pipe wall at a 1/4 part of each sampling chamber from top to bottom, and a sampling window is arranged on a pipe wall of each lower half part at the height of 1/2; one side of each sampling window is hinged to a window door through a hinge, and an arc-shaped inserting hole and a handle are formed in and arranged at the other side of each sampling window and the corresponding window door respectively; the inserting holes and the handles are fixedly connected through bolts to close the window doors; a funnel with an upward trumpet opening is arranged between the flow guide hole of each sampling chamber and the corresponding sampling window, and the edge of the opening of each funnel is fixedly connected with the inner wall of the corresponding sampling chamber; a bottom plate of each sampling chamber is a sample carrying platform; a liquid collection bottle is arranged on each sample carrying platform; a liquid outlet of each funnel stretches into a bottle opening of the corresponding liquid collection bottle. The device disclosed by the invention can be repeatedly utilized and is convenient to wash; the device is simple, and is easy to operate; technicians can easily learn and grasp the utilization of the in-situ stratified sampling device.

The invention relates to an urban land utilization change simulation cellular automaton method based on a BSVC method. The method comprises the following steps: 1) supervising and classifying remote sensing images to obtain an urban land utilization classification map; 2) obtaining urban land utilization change driving factor data, and performing preprocessing; obtaining effective sample points ofthe land utilization map and the driving factor through a random stratified sampling method; 3) training the effective sample points by using a Bayesian space variable coefficient (BSVC) method to obtain a conversion rule of the cellular automaton; 4) obtaining the urban land utilization conversion probability according to the CA conversion rule established by the BSVC; 5) establishing a CA model(CABSVC) based on the BSVC; the urban land use change simulation method based on the CABSVC model has the advantages of being higher in simulation precision and better in urban land use change simulation capacity compared with the prior art, and realizing evaluation through the overall precision (OA) and the figure goodness (FOM).

The invention discloses a brain age prediction method based on a 3D convolutional neural network. The method comprises the following steps: performing stratified sampling on brain nuclear magnetic resonance imaging data; inputting the brain nuclear magnetic resonance imaging data subjected to stratified sampling into a 3D convolutional neural network through multiple threads for training, and extracting feature data; constructing a brain age prediction regression model according to the extracted feature data; and outputting a brain age prediction result according to the brain age prediction regression model. According to the method and the device, the technical problem of inaccurate children brain age prediction caused by information loss in the aspect of feature selection of a traditionalmachine learning model in related technologies is solved, and the technical effect of improving the accuracy of children brain age prediction is achieved.

The invention provides a stratified sampling device for grains. The stratified sampling device comprises a body, wherein the body is a single-layer cylinder; the inside of the cylinder is partitioned into a plurality of cavities by using partition plates; openings are formed in the side walls of all the cavities; each opening is provided with a baffle; each baffle is provided with a pressure sensor; and each pressure sensor is connected with a power source arranged in the cylinder and is connected with an electric switch for controlling the corresponding baffle. Due to the adoption of the technical scheme, the stratified sampling device is the single-layer cylinder so as to be simple in structure and low in cost; and meanwhile, due to the arrangement of the pressure sensors, as long as the stratified sampling device for grains is inserted to grains, the baffles can be automatically opened, and samples can flow into the corresponding cavities, so that the stratified sampling device for grains is convenient to use.

The invention relates to the technical field of sample collecting devices, in particular to a liquid stratified sampling device .The device comprises a sampling tube and a sampling support .The sampling tube is formed by connecting a plurality of sampling tube units end to end .Each sampling tube unit comprises a tube body, a stop valve and a rack .The lower end of each stop valve is in sealed fixed connection with the upper end of the corresponding tube body .Matched sealed connection mechanisms are arranged at the lower end of each tube body and the upper end of the corresponding stop valve .The uppermost stop valve is provided with a stop valve switching device .The sampling support comprises a base plate, a longitudinal beam and a guide rail .The longitudinal beam is rotationally mounted on the base plate, the base plate is provided with a first motor for driving the longitudinal beam to rotate, an electric telescopic device is arranged between the guide rail and the longitudinal beam, a gear and a second motor for driving the gear to rotate are mounted on the guide rail, and the rack can slide perpendicularly along the guide rail and is engaged with the gear .The liquid stratified sampling device is high in sampling precision, large in sampling range, easy and convenient to operate, high in automation degree and easy to carry, and the original state of a sample can be observed visually.

The invention discloses an integrated apparatus used for potting test soil stratified sampling. The integrated apparatus comprises a potting container and a soil sampler; the potting container is a container with an opening at the top; the periphery wall of the container is provided with multiple sampling holes, and each sampling hole is provided with a sealing rubber plug for sealing or opening the hole; the soli sampler comprises an outer cylinder and an inner push rod nested in the outer cylinder; the front end of the outer cylinder is provided with an observation groove, and the upper side of the observation groove is provided a row of limit screw holes distributed at the transverse direction; the front end of the inner push rod is also provided with limit screw holes corresponding to the limit screw holes in the outer cylinder; the outer cylinder and the inner push rod are movably fixed by inserting position-clamping screw spikes into the limit screw holes in the outer cylinder and the inner push rod; and the tail end of the inner push rod is also connected with a handle. By ingeniously combining the potting container and the soil sampler, uniform accurate stratifying and multi-point mixed sampling can be performed on the potting test soil, so that the accuracy, the representativeness and the comparability of soil test data are guaranteed.

The invention provides an electric energy quality reference level evaluation method and system. The method comprises the following steps of acquiring sampling data of each monitoring area of a power grid system by adopting a stratified sampling method; according to the sampling data, calculating a characteristic value of each preset power quality level index; calculating the electric energy quality level value of the monitoring area by adopting an entropy weight method according to the characteristic value of each preset electric energy quality level index; generating an electric energy quality reference level value according to the electric energy quality level value of each monitoring area; and evaluating the electric energy quality of each monitoring area according to the electric energy quality reference level value and the electric energy quality level value of each monitoring area to generate an evaluation result. By implementing the method and the device, the evaluation standards are provided for the electric energy quality of different regions, the evaluation of the electric energy quality is realized, the accuracy of an evaluation result is ensured, the processing efficiency is improved, the difference of the electric energy quality levels of different regions can be intuitively reflected, and a basis is provided for making accurate electric energy quality level improvement measures.

The invention relates to a stratified sampling device for a water body at any depth. The stratified sampling device effectively solves the problem that multiple layers of water samples at any depth cannot be taken at a time. According to the technical scheme, the device comprises a vertical plate, a plurality of water collecting tanks are fixed to the front side face of the vertical plate, pistonsare installed in the water collecting tanks, and vertically-through through grooves are formed in piston rods; a first shifting rod is hinged to the left end face of the water collecting tank, a groove is formed in the piston rod, a guide rod is installed on the left side of each vertical plate, and a compression spring enabling the guide rod to reset downwards is installed at the lower end of each guide rod; a plurality of protruding blocks are mounted on the guide rods; the distance between the protruding blocks and the piston rods is sequentially reduced from top to bottom. The upper endsof the guide rods are connected with ropes, and a plurality of buoys of which the positions can be randomly adjusted are arranged on the ropes; by moving the position of each buoy, the submerging depth is adjusted, the water collecting depth of each water collecting tank can be freely adjusted, meanwhile, sampling is accurate, and samples cannot be polluted.

The invention discloses an automated water stratified sampler and application thereof. The automated water stratified sampler comprises a remote control boat (2), a water sample collecting device, a signal receiver (7) and a ship body motor (17), wherein the signal receiver (7) and the ship body motor (17) are arranged on the remote control boat (2). The water sample collecting device comprises a water sample water-containing container (3), a central data processor (4), an intelligent sample collecting motor (5), a water sample water injection pipe (8) and a water sample collecting pipe (9). The automated water stratified sampler is suitable for various special field sampling, environment protection monitoring, water treatment, liquid treatment and environment water body sampling, and can perform stratified sampling of different depths on liquid. The automated water stratified sampler is convenient to carry and suitable for a place without a power supply. The automated water stratified sampler is specially used for field water sample collection and used for water sample collection of surface water of rivers, lakes and reservoirs and the like within a depth of 0-30 m.

The invention provides a credibility-based random forest soil heavy metal risk evaluation method and system, and the method comprises the steps: carrying out the data preprocessing: carrying out the preprocessing of an original data set, and obtaining an unmarked data set; marking data, namely marking whether the samples in the data set have pollution risks or not by adopting a soil pollution evaluation method; dividing a data set, namely performing stratified sampling on the data set according to proportions of different categories, and dividing a training set and a test set; model training: learning the training set by using a random forest algorithm based on true positive rate weighted voting to obtain a risk evaluation model, and inputting the test set into the model to obtain a risk evaluation result, using a Bayesian optimization algorithm to find a parameter combination with the highest accuracy rate by taking the accuracy rate as an optimization target, and and carrying out soil heavy metal risk evaluation and evaluation by utilizing the trained model. According to the method, the recall rate of few types of samples is improved on the unbalanced data set, and the pollution-free risk of the samples can be accurately distinguished.

The invention discloses a soil remediation sampler for stratified sampling of soil. The invention relates to the technical field of soil remediation. The soil remediation sampler for stratified sampling of soil comprises a sampling main cylinder, an air groove is annularly formed in the inner side wall surface of the sampling main cylinder, an inner cylinder is arranged on the inner side of theair groove; an extrusion transmission groove is annularly formed in the side wall of the top of the inner side of the inner cylinder; according to the soil remediation sampler for stratified samplingof soil, after Sampling is finished, a lower rod is controlled by control equipment to be lifted up; therefore, an extrusion block on the gas control equipment ascends and extrudes the interior of the inner cylinder to extrude gas above the extrusion block; the air groove, the extrusion transmission groove and an inflation groove are used for conducting, so that the air above the extrusion blockis impacted and extruded into a closed air bag on a closed device, the closed air bag is inflated and expanded to be reset and closed, and the effect of completely taking out sandy soil is achieved.

The invention relates to an underground water stratified sampling device which comprises a sampling barrel with a fixing frame, a sampling inner pipe and a sampling outer pipe, and the sampling barrel is in threaded connection with the sampling outer pipe; wherein a plurality of partition plates are arranged in the sampling inner tube, the inside of the sampling inner tube is divided into a plurality of sampling cavities by the partition plates, a sampling air bag is arranged in each sampling inner cavity, an air pipe is arranged in the sampling inner tube, each sampling air bag is communicated with an air pump arranged on the fixing frame through the air pipe, a plurality of sampling inner holes are formed in the sampling inner tube, and at least one sampling inner hole is formed in the side wall of each sampling cavity; a plurality of sampling outer holes are formed in the sampling outer pipe, and the sampling outer holes in the sampling outer pipe correspond to the sampling inner holes in the sampling inner pipe one by one; a plurality of filtering windows are arranged on the sampling barrel, and each filtering window corresponds to the sampling outer hole in position; a balancing weight is arranged at the bottom of the sampling outer pipe. By means of the device, water samples of different aquifers can be collected from a single sampling well, the device is suitable for a phreatic bed of a single structure and a confined aquifer of a multi-layer structure, and the occupied area of a drill hole and the construction cost can be effectively saved.

The invention discloses a stratified sampling device for columnar sediment. The device comprises a sampling head; the bottom of the sampling head is fixedly connected with the top of a sampling tube assembly in a sealing way by means of a flange, and guide wing pieces are arranged around the sampling head; the sampling head comprises a connecting part, a connecting rod, a sliding counter weight hammering block and a connecting rope; the connecting rod is fixedly arranged on the connecting part; the sliding counter weight hammering block is arranged on the connecting rod in a sliding way; the connecting rope is connected with the sliding counter weight hammering block; a sampling column assembly comprises a single-sided sliding sealed square hollow sampling column and a bottom sealing mechanism; the upper end of the single-sided sliding sealed square hollow sampling column is fixedly connected with the bottom of a connecting end of the sampling head by means of a flange; a bottom sealing mechanism is arranged at the lower end of the single-sided sliding sealed square hollow sampling column. According to the stratified sampling device, the sampling head and the sampling column assembly which are respectively arranged on the top and at the bottom are sampling seal facilities, so that a double-insurance effect is achieved; the sampling tube diameter can be very easily increased, sothat more sediment samples to be taken can be obtained at a time.