34results about How to "Good detection performance" patented technology

In summary, the invention relates to a device, a system, a method and a computer program for spectrum sensing. A detection procedure for detecting a signal of interest or an event by using a plurality of sensing devices capable of communicating with a central unit is proposed. The sensing devices can compute soft detection metrics and communicate this information to a central unit, where the information may be used to make a final detection decision using a certain specified rule. The signaling overhead of the proposed approach can be of the same order as that of a hard signaling approach. However, the proposed approach may achieve a better detection performance.

The invention discloses a low-complexity signal detection method for an MIMO FBMC-OQAM (Multiple Input Multiple Output Filter Bank Multicarrier Offset-QAM) system. According to the method, channel matrix characteristics are combined with a list sphere detection algorithm; QR decomposition is carried out on an equivalent channel matrix subjected to imaginary and real separation, and the internal interference of the MIMO FBMC-OQAM system is completely eliminated through utilization of obtained unitary matrix orthogonal characteristics; signals are detected through adoption of the list sphere detection algorithm, and a candidate solution vector list is generated through a Grover quantum search algorithm; and a likelihood ratio is solved through utilization of soft information carried in the list, thereby obtaining bit-level output. According to the method, the problem that in the MIMO FBMC-OQAM system, high-order modulation complexity is relatively high is effectively solved through adoption of the Grover quantum search algorithm; the computing complexity is reduced to a certain degree; and the good detection performance is ensured.

The invention provides a detection method and device for covert channel communication based on an ICMP protocol, and relates to the field of communication, and the method comprises the steps: analyzing an obtained ICMP flow message, and obtaining a transmission identification and a transmission content; judging whether the transmission content is messy or not; if the transmission content is messy,judging whether the request content and the response content corresponding to the target transmission identifier are the same or not; and if the request content and the response content correspondingto the target transmission identifier are different, determining a covert channel communication behavior based on the target transmission identifier. Whether the covert channel communication behaviorbased on the ICMP exists or not is recognized based on flow analysis, the performance requirement for detection equipment is lowered, the detection efficiency is improved, meanwhile, use of a networktroubleshooting tool is not affected, and normal operation of a network is facilitated.

The invention provides a voice activity detection method and system. The method comprises the steps: calculating the spectrum density of a current frame of an audio signal; estimating an expected value of the spectrum density of noise; calculating the signal to noise ratio of the current frame based on the spectrum density of the current frame and the spectrum density of noise; and generating a voice activity detection result based on the signal to noise ratio of the current frame and a preset threshold. Therefore, the voice activity detection result is related with the probability statistics distribution of noise, thereby overcoming the impact on the detection result from noise. Meanwhile, the preset threshold is a dynamic threshold and is related with the change of noise, thereby enabling the detection result to be adapted to the noise environment of the current frame.

The invention belongs to the technical field of photoelectric detectors, and concretely relates to p-n junction self-driven solar blind ultraviolet detector based on an organic-inorganic composite structure and a preparation method thereof. The structure of the device includes a substrate, a n-type gallium oxide micron wire, a p-type organic conductive polymer nano film, and metal contact electrodes prepared on the p-type and n-type layers. The characteristics of the self-driven solar blind ultraviolet detector with the organic-inorganic composite structure are that a core-shell structure is formed by the p-type organic conductive polymer nano film and the n-type gallium oxide micron wire, and so the self-driven solar blind ultraviolet detector has good photoelectric characteristics and deep ultraviolet selectivity when operated under zero bias voltage. The device solves the problem that a p-type material in a conventional inorganic semiconductor deep ultraviolet photodetector of a p-nstructure cannot be controllably prepared. The detector of the invention is simple in preparation process and has great application prospect in the field of solar blind ultraviolet detection.

The invention discloses an adaptive subspace detector under an unknown interference in a partially uniform environment. The detector comprises the following technical steps of: firstly, performing singular value decomposition on a signal guiding matrix, and acquiring a basis matrix corresponding to an interference alternative subspace; performing interference whitening and matching and filtering on the data to-be-detected by the basis matrix and a sampling covariance matrix; performing whitening and filtering on the data to-be-detected by using the sampling covariance matrix; calculating the difference between the output of the whitening and matching and filtering of the data to-be-detected and the output of the interference whitening and matching and filtering of the data to-be-detected,and then performing an normalization operation to form a detector; determining a detection threshold according to the detector and a preset false alarm probability by using a Monte Carlo method; comparing the detector output to a detection threshold, and determining that the target is exist, if the former is greater than the latter, and otherwise, determining that the target does not exist. According to the adaptive subspace detector under the unknown interference in the partial uniform environment, compared with traditional detection methods, the detection method is compared with a traditional detection method, the method provided by the invention has a better detection performance in the unknown interference environment, and has CFAR (Constant False-Alarm Rate) characteristics and does not require an independent CFAR processing.

The invention provides a repeating data deleting algorithm in cloud storage. Energy aggregation and noise inhibition of repeating data information flow of a cloud storage system are realized by four-order cumulant slicing, repeating data detection post filtering processing is carried out, and information flow feature encoding of a plurality of threads is created to delete the repeating data. The repeating data deleting algorithm provided by the invention avoids wrong deletion and miss deletion caused by interference features of the data information flow; the performance for detecting the repeating data in the cloud storage system is good; the accuracy of deleting the repeating data is high; and the comprehensive performance is better than that of the traditional algorithm.

The invention discloses an anti-HE4 nano antibody, the nano antibody has three unique complementary determining regions CDR1, CDR2 and CDR3, the invention also provides an expression vector containing a encoding sequence of a variable region of the nano antibody, a host cell containing the expression vector, and an application of the nano antibody in detection of HE4 content in serum. The nano antibody provided by the invention has specific recognition and binding ability to HE4, the affinity of the nano antibody can reach 1.009 E-09, and the nano antibody has a unique antigenic determinant recognition site and can obtain an excellent detection effect in HE4 serum detection by using a double-antibody sandwich method.

The invention relates to a paper micro-fluidic chip. The paper micro-fluidic chip can integrates the extraction, purification and isothermal amplification of nucleic acids and result interpretation, the whole detection process takes only 30 minutes, a pump, a centrifuge or a thermal cycler is not needed, and results are interpreted with naked eyes. The lowest detection limit of the paper micro-fluidic chip to group A rotavirus infected samples is 10<3> copies / ml, and the sensitivity and the specificity of the chip, verified with 48 clinic samples reach 100% respectively. The microfluidic chip has the advantages of convenience, high efficiency, low cost and good detection performance; the extraction and purification time of nucleic acid is only 5 minutes, so the chip can replace traditional nucleic acid extraction methods (such as nucleic acid extraction using a magnetism bead takes 1 hour) to effectively shorten the detection time; and the paper microfluidic chip can be used in a central laboratory or at bedside, so the chip can be a powerful tool for detecting related pathogens (such as group A rotavirus).

The invention discloses an anti-HE4 nanobody, the nanobody has three unique complementary determining regions CDR1, CDR2 and CDR3, the invention also provides an expression vector containing a coding sequence of a variable region of the nanobody, a host cell containing the expression vector, and application of the nanobody in detection of HE4 levels in serum. The nanobody provided by the invention has specific recognition and binding capacities to HE4, and the affinity of the nanobody can reach 7.020 E-10; and the nanobody has a unique antigenic determinant recognition site, so that an excellent detection effect in HE4 serum detection can be obtained, especially in a double-antibody sandwich method.

The invention discloses an anti-AFP nanometer antibody. The nanometer antibody has three unique complementary determining regions CDR1, CDR2 and CDR3. The invention also provides an expression carrier which contains a nanometer antibody variable region coding sequence, a host cell containing the expression carrier, and application of the nanometer antibody in preparation of tumor preparation medicines and tumor diagnosis reagents. The nanometer antibody provided by the invention has a specific recognizing and binding capacity for AFP, the affinity of the nanometer antibody can be 3.082E-09, the nanometer antibody has a unique antigenic determinant recognition site and has an obvious ADCC effect for cancer cells, and an excellent detection effect can be obtained in AFP serum detection, especially in a double-antibody sandwich method.

The present invention provides a two-state Viterbi detection system and method. The system comprises a time domain to frequency domain conversion module for converting an inputted time domain sample point signal into a frequency domain sample point signal, a difference judgment module for obtaining a judgment bit and a judgment variable, a phase error calculation module for calculating errors to obtain judgment error variables, a frequency domain two-state Viterbi module for carrying out the combined detection of the multiple judgment error variables and obtaining corrected judgment error variable values, a cache module for storing the judgment bit so as to match the processing time delay introduced by the frequency domain two-state Viterbi module, and a judgment bit correction module which corrects the judgment bit by using the corrected judgment error variables. The system and the method have the advantages that good detection performance can be obtained, the system complexity can be reduced, and the system and method are not sensitive to an h value, a frequency shift, a phase, a matched filter, and other factors.

The invention provides a constant false alarm detection method and device for radar detection, electronic equipment and a storage medium, and belongs to the technical field of radar signal processing, and the method comprises the steps: obtaining the sample data of at least one radar frame, and generating a corresponding distance-Doppler scattering center energy matrix; for each radar frame, based on the corresponding distance-Doppler scattering center energy matrix, determining a truth value of noise energy estimation of each distance unit, calculating a target noise energy estimation coefficient of each distance unit and a target detection threshold coefficient of each distance unit, and calculating a reference detection threshold value of each distance unit; and performing constant false alarm detection on the Doppler dimension scattering center of the radar detection data based on the reference detection threshold value of each distance unit. According to the invention, target detection under a non-uniform clutter distribution condition can be realized, and ideal detection performance can be achieved.

The invention relates to a deep learning-based power transmission and transformation project quality common problem prevention and detection method, which comprises the following steps of S1, obtaining power transmission and transformation project power box grounding connection detection data, and performing preprocessing; S2, constructing a power transmission and transformation project power boxgrounding connection detection data set according to training algorithm requirements; S3, adjusting and optimizing training hyper-parameters of a deep learning algorithm yolov4tiny, optimizing the training model by adopting an optimization algorithm, and performing training according to the data set to obtain a yolov4tiny detection model; S4, performing target detection on the input picture according to the yoov4tiny detection model obtained after training, and obtaining a preliminary detection result; S5, decoding the preliminary detection result, screening out a final detection result by adopting an improved non-maximum suppression algorithm, and finally drawing a detection box in the input picture. The method can effectively identify and judge whether the power box is in grounding connection or not, has good generalization ability and robustness, and can have good detection performance in a complex environment.

The invention provides a multiple-input-multiple-output detection method, which comprises the following steps: establishing a transmission channel matrix H; fixing one emission signal xi in the ith layer of transport layer, and selecting one constellation point in constellation points determined according to a preset digital modulation mode from the value of the emission signal; removing the emission signal xi from an emission signal set, updating the emission signal set and forming an emission signal update set X-i, and meanwhile, removing a corresponding transmission channel column and forming a transmission channel update matrix H-i, and carrying out updating and forming a received signal update set R-i; and obtaining likelihood probability of each emission signal in the emission signal update set X-i through a pre-stored sorted QR decomposition algorithm, obtaining constellation point position of each emission signal through hard decision, merging the X-i and xi to obtain a group of decision under the constellation point selected for the xi, and carrying out the steps above on all emission signals of the ith layer of transport layer and all of the transport layers to obtain a decision emission signal set, and carrying out calculating to obtain an emission signal therefrom according with the maximum likelihood standard. The multiple-input-multiple-output detection method is excellent in detection performance, and lower in complexity than an existing detection algorithm.

The invention relates to the field of materials, and particularly discloses a preparation method of a titanium alloy substrate with excellent detection performances on hydrogen peroxide. According tothe invention, the preparation method adopts KOH solution with a certain concentration, and a nickel-titanium alloy sheet is corroded at a low temperature for a short time in a hydrothermal environment, and the potassium titanate composite material with a sheet-shaped structure and a nickel hydroxide and nanowire structure is directly obtained on the surface of the nickel-titanium alloy sheet. Thepreparation method is simple, and the prepared material Ni(OH)2 / K-Ti-O has high sensitivity, low detection limit and good selectivity on hydrogen peroxide.

The invention discloses a triethylamine gas sensor based on a sulfur-rich vacancy ZnIn2S4 nanoflower sensitive material assembled by {0001} crystal face nanosheets and a preparation method of the triethylamine gas sensor, and belongs to the technical field of gas sensors. The device is composed of an Al2O3 substrate, a Pd metal interdigital electrode and a sulfur-rich vacancy ZnIn2S4 nano sensitive material layer from bottom to top, wherein the Pd metal interdigital electrode is coated with the sulfur-rich vacancy ZnIn2S4 nano sensitive material layer, and the sulfur-rich vacancy ZnIn2S4 nano sensitive material layer is assembled based on {0001} crystal face nanosheets. The ZnIn2S4 nanoflower sensitive material is synthesized by changing synthesis conditions, ZnIn2S4 nanoflowers grown through S defect engineering control are formed by self-assembly of nanosheets with exposed high-energy {0001} surfaces, and the surfaces of the ZnIn2S4 nanoflowers have a large number of S vacancies capable of serving as sensing reaction active sites, so that the ZnIn2S4 nanoflowers have good detection performance on triethylamine gas. Meanwhile, the process adopted by the invention is simple, and the manufactured device is small in size and suitable for mass production, thereby having important application value.

The invention relates to a network node and a user device. The network node (100) comprises a processor (102) configured to determine a resource indicator (110) comprising a first start index (I1) anda first number of frequency resources (N1), wherein the first start index (I1) and the first number of frequency resources (N1) are used for allocating a first set of contiguous frequency resources (R1) within a first sub-band, and a corresponding first set of contiguous frequency resources (R1') within a second sub-band, wherein the first sub-band and the second sub-band are non-overlapping andcomprise equal number of frequency resources, a transceiver (104) configured to transmit a transmission grant (120) comprising the resource indicator (110) to a user device (300). The user device (300) comprises a transceiver (302) configured to receive a transmission grant (120) comprising a resource indicator (110) from a network node (100), the resource indicator (110) comprising a first startindex (I1) and a first number of frequency resources (N1), wherein the first start index (I1) and a first number of frequency resources (N1) are used for allocating a first set of contiguous frequencyresources (R1) within a first sub-band, and a corresponding first set of contiguous frequency resources (R1') within a second sub-band, wherein the first sub-band and the second sub-band are non- overlapping and comprise equal number of frequency resources; a processor (304) configured to derive the first start index (I1) and the first number of frequency resources (N1) based on the resource indicator (110); wherein the transceiver (302) is configured to transmit data symbols to the network node (100) using the first set of contiguous frequency resources (R1) and the corresponding first set of contiguous frequency resources (R1'). Furthermore, the invention also relates to corresponding methods, a wireless communication system, a computer program, and a computer program product.

The invention discloses a nondestructive detector for implementing detection based on ultrasonic diffraction signals. The nondestructive detector comprises a host and a scanning device; the host is provided with a human-computer interactive hardware platform and connected with a display screen, an operation panel, various electric and data interfaces, a main control computer, an ultrasonic functional module and storage equipment; the scanning device comprises a time of flight diffraction (TOFD) probe, a position coder and a scanning frame, wherein the TOFD probe is a piezoelectric composite probe with wideband narrow pulse special for TOFD detection; the position coder is a high-precision rotary coder and is used for recording the movement position of the TOFD probe during scanning; and the scanning frame is used for fixing the distance of the probe and installing the rotary coder. The probe has the advantages of reasonable structure, good detection performance, small volume and convenience for carrying.

The invention discloses a character interaction detection method based on a bidirectional attention mechanism under knowledge guidance. The character interaction detection method comprises the following five steps of target detection, grouping, bottom-up encoder, top-down encoder and binary classification. The key of character interaction detection on multiple person and object instances existing in a complex scene is that relation modeling analysis is effectively carried out on objects in the scene, and a knowledge-guided top-down attention mechanism is introduced into a character interaction detection task. The model can adaptively search related information in a scene for a given human-object pair so as to carry out interaction behavior discrimination, so that human interaction detection is realized; the method provided by the invention has better detection performance (mAP) and better interpretability.