198 results about "Automatic threshold" patented technology

An implantable cardiac rhythm management device operable in an autothreshold or autocapture verification mode, wherein the rhythm management device is capable of detecting noise that affects signal characteristics of a sensed intracardial evoked response electrogram signal. The device includes a noise detection circuit that determines whether a minimum peak timing occurs during a predetermined time following delivery of a stimulation pulse. If a minimum peak timing occurs during the predetermined time following delivery of the stimulation pulse, then significant amounts of noise affecting the signal characteristics of the electrocardiogram signal is assumed.

The invention provides a method for the outline automatic extraction of a level set medical ultrasonic image area based on an edge and a statistical characteristic, aiming at the characteristics of low contrast degree and small signal-to-noise ratio of medical ultrasonic images and designing a method for the outline extraction of the level set area based on the edge and the statistical characteristic. The method comprises three steps of: 1, carrying out area outline coarse extraction, completing image inverse extraction and self-adapting Gaussian function background suppression, applying otsu image automatic threshold algorithm to convert the image into a binary image, and carrying out image degreasing interference operation and closed area outline extraction work; 2, adopting a selectivity aeolotropy medical ultrasonic image smoothing algorithm to pre-treat an original image; and 3, carrying out the precise extraction of the level set image area based on the edge and the statistical characteristic. Experimental results indicate that compared with the prior method, the method of the invention can obtain a more precise partition result.

System and method for improving the detection performance of a wirelessly transmitted signal. A preferred embodiment comprises specifying a desired response for missed channel detection and false alarm probabilities for a plurality of signal qualities and determining if a channel detection threshold is based on missed channel detection or false alarm probabilities for the plurality of signal qualities. A signal quality estimate of a channel can be inferred from a signal quality measurement of a second channel, wherein the channel and the second channel are sourced by a single transmitter. The channel detection threshold can be adjusted based upon the previously determined required response and the signal quality estimate of the channel.

The invention relates to an intermediate frequency direct sequence spread spectrum receiver for satellite ranging, which consists of 37 parts of a front-end A/D, an FFT module, a local PN code generator, a correlator, an automatic threshold calculation module and the like. The connection relationship is as follows: the output of the front-end A/D and the output of a carrier tracking loop NCO are respectively connected to an in-phase branch multiplier and an orthogonal branch multiplier, the input of the front-end A/D and the input of the carrier tracking loop NCO enter into an in-phase branch FIR low-pass filter and an orthogonal branch FIR low-pass filter, consequently, on the one hand, the output is sent to an integral zero clearing device, then the output which is sent to the FFT module, a branch 1 local PN code memory ROM and a branch 2 local PN code memory ROM enters into a branch 1 complex multiplier and a branch 2 complex multiplier, the output is sent to a branch 1 root mean square module and a branch 2 root mean square module, the output is sent to the threshold calculation module and a capturing and judging module for carrying out code catching; and on the other hand, the output is sent to the correlator and the local PN code generator for carrying out code tracking. The output of the correlator is simultaneously sent into a frequency discriminator/phase discriminator of the carrier tracking loop and then enters into a loop filter of the carrier tracking loop, and the output of the loop filter of the carrier tracking loop enters into the carrier tracking loop NCO for carrying out carrier tracking.

The invention discloses a system and methods for quantitating the presence of nucleic acid sequences by evaluation of amplification data generated using real-time PCR. In one aspect, the methods may be adapted to identify a threshold and threshold cycle for one or more reactions based upon evaluation of exponential and baseline regions for each amplification reaction. The methodology used in the analysis may be readily automated such that subjective user interpretation of the data is substantially reduced or eliminated.

A method for automatic threshold control and detection of lead failure in an implanted medical device obtains three sensing vectors for measurement of an electrocardiogram signal. A dynamic error signal is determined from the vectors, and may be used to set a detection threshold for insufficient ECG signals, and/or to passively monitor the device for indications of lead failure without performing an impedance measurement. Passive mode operation conserves battery power and enables continuous lead integrity checks. A quality factor may also be determined from the error signal, to indicate whether or not signal measurements are valid with respect to noise levels. If the detection threshold is allowed to decay between successive features of the electrocardiogram, the decay rate may be made adaptive such that it automatically adjusts to changes in heart rate or to changes in amplitude of the electrocardiogram features.

The invention discloses a preprocessing method and a preprocessing system used for extracting breast regions in mammographic images. The method includes steps: subjecting the mammographic images to automatic threshold segmentation to obtain binary images; subjecting communicated regions in the binary images to filling processing to remove labels and holes in the mammographic images; dividing the binary images into a plurality of subregions, and binarizing each subregion according to local threshold value to position breast contour regions; subjecting the binary images and the breast contour regions to set 'and' operation, searching number of pixel points in each subregion containing difference in the binary images along a reference line from top to bottom, and positioning the subregion with maximum number of pixel points in regions containing difference to be nipple regions. By overall automatic threshold segmentation and local threshold analysis, the breast regions and the nipple regions in the mammographic images can be accurately positioned, the preprocessing process is low in computation complexity, and execution efficiency is high.

Disclosed are systems and methods for identifying and quantitating the presence of one or more DNA species in a sample population through PCR amplification. DNA species quantitation includes a determination of a threshold fluorescence value used in the assessment of the PCR amplification reaction. Various embodiments of the present invention incorporate an enhancement function useful in selecting appropriate threshold fluorescence values and facilitate the determination of DNA concentrations by quantitative PCR based methodologies.

A method and system for selecting a threshold for use in detecting anomalous objects, or targets, in images with a tractable false alarm rate. A method includes steps of identifying a number of peak values from a plurality of values; calculating an average peak value from the identified peak values derived in the previous step; and calculating the threshold according to the average peak value; the number of identified peak values; and a predetermined number of false alarms. In this manner, object classifications are accurate; the number of false alarms is reduced; and redundant classifications are minimized for each image.

An implantable cardiac stimulation system capable of automatic capture verification is provided with an associated method for performing automatic testing functions using programmable, or automatically determined, AV delays. Automatic threshold testing and evoked response sensitivity testing performed at a user-specified AV delay setting, rather than a preset setting, allows assessment of automatic capture verification based on an AV delay relevant to daily system function. Further features of the present invention are an adjustable frequency with which automatic threshold tests are performed and an adjustable frequency with which threshold test results are stored in memory in a threshold record for better monitoring of lead stability or impending clinical problems. The frequency of performing threshold tests and the frequency of storing threshold test results may be varied according to the threshold stability. Stored threshold test results are advantageously displayed with respect to a fixed or variable time scale.

The invention provides an automatic SAR (synthetic-aperture radar) image rectification method. In the method, the problems encountered when feature points are selected by SIFT (scale-invariant feature transform) rectifying points under the condition of SAR image complex landforms are analyzed, the feature points are combined with the Delaunay triangulation network and coded, and triangle similarity of coded feature points are judged through automatic threshold values according to the Delaunay triangularization principle. Since SIFT rectification and the Delaunay triangulation network have robustness to geometric changes such as rotation, wrong rectifying points rectified by the SIFT can be filtered by the SIFT-Delaunay encryption algorithm according to the similarity among triangles, and accurate rectification can be achieved.

A mold monitoring method based on a FAST-9 image characteristic rapid registration algorithm include the following process: when mold open of an injection molding machine is in place and after an ejector pin is ejected, standard form images are acquired respectively; operating state information of the injection molding machine is waited, when the injection molding machine is operated to the place of the mold open, images of surfaces of a mold cavity are taken continuously through a camera, current frames of the monitored images are preprocessed, and preparations are made for subsequent image rapid registration; the FAST-9 image characteristic rapid registration algorithm is carried out; after registration, differences are made between the current frames and the form images; through adoption of the ostu automatic threshold value partitioning algorithm, binaryzation of the images is achieved, and continuous closing and opening operation is conducted on the images; whether anomaly exists in molding of products is checked through electron hole detection, when the anomaly exists, alarm information is displayed; otherwise, the operating state information of the injection molding machine in the next period is waited. The mold monitoring method based on the FAST-9 image characteristic rapid registration algorithm is good in real-time performance and strong in robustness.

A queue buffer control system is described, in which a queue length parameter QL is compared with a length threshold value Lth for triggering a congestion notification procedure that comprises a decision procedure for deciding whether to perform congestion notification or not. Also, an automatic threshold adaptation procedure S5 for adapting the threshold Lth on the basis of an estimated link capacity value LC is provided. The automatic threshold adaptation procedure S5 is operable notification in one of at least a first and a second adaptation mode, the first adaptation mode being associated with minimizing queuing delay and adapting the threshold value Lth on the basis of n·LC, where n≧1, and the second adaptation mode being associated with maximizing utilization and adapting the threshold value Lth on the basis of m·LC, where m>1 and m>n.

The invention belongs to the field of network security situation awareness, and particularly relates to a network security situation awareness analysis method based on log and SNMP information fusion. The method includes the steps of performing data collection based on log and SNMP data fusion, performing preprocessing based on log and SNMP data fusion, performing log data analysis and SNMP data analysis, performing log and SNMP data fusion and performing visualization on log and SNMP data fusion. Compared with a method for analyzing log data or SNMP data sources singly, through combination of the two kinds of data, the overall operation trend of the network situation can be well analyzed, and analysis is more comprehensive and more accurate. According to a system, data with a high important degree is selected to be processed according to user requirements, and the burden of processing a large number of data is relieved. An automatic threshold value correction method is used, therefore, threshold value parameters defined by a user are more accurate, and the accuracy of data fusion is improved.

The invention discloses an intelligent potato sorting method and apparatus, comprising a mechanical potato sorting apparatus, a potato grading control method and a potato appearance quality detection method. A potato intelligent grading apparatus is formed by additionally installing a computer vision detection device and an intelligent grading control device on the basis of the mechanical potato sorting apparatus. The potato grading control method comprises a shooting control unit and a grading control unit. The potato appearance quality detection method comprises the following steps: image acquisition and preprocessing; shape detection; green skin detection; and defect detection. The shapes of potatoes are graded by calculating ovality by using an approximate ellipse method according to national standards of China and external characteristics of the potatoes; the phenomenon of green skin is detected by using the values of an R component and an H component according to color characteristics; defects are detected by using automatic threshold segmentation and are determined according to the area ratio of the defects. The grading apparatus and grading method provided by the invention overcome the disadvantages of subjectivity, low efficiency and the like of artificial detection, enable quantitative detection to be more objective and scientific, are applicable to quality grading and commerce circulation of produced potatoes and improve production efficiency.

In a water resource remote sensing survey, water body information is required to be extracted by using a middle-high-resolution image along with fine management of the water resource. However, since a high-resolution satellite image has fewer bands, the construction of an automatic water body extraction model is not facilitated, and further relatively fewer methods for effectively extracting water body information are available, and the error extraction rate and the extraction omission rate are higher. The invention constructs a new SPOT5 image-based automatic water body extraction method. According to the method, the polarization of the grey value of a water body is realized by constructing a calculation model capable of homogenously enhancing a water body index and multiple indexes based on remote sensing image background value research, and high-precision automatic extraction of the water body is realized on the basis by using improved automatic threshold selection algorithm, mathematical morphological filtering algorithm and thinning algorithm and the like. Experimental comparison shows that the influence of topographic shadowing, an inhabited place and the like can be eliminated to the greatest extent, a larger water body can be effectively extracted, and higher extraction precision on a finer water body is realized.

The present invention discloses an image detection method for detecting a foreign body in an airport runway. The method comprises: manually inspecting an airport runway, and after determining no foreign body, acquiring a frame of background image of the airport runway by using a sensor; acquiring a current image of the airport runway in real time by using the sensor; by means of a feature matching algorithm, performing registration on the current image and the background image; performing a differential operation on the current image and the background image, to obtain a background difference image of the current image; performing automatic threshold binarization on the background difference image of the current image, to obtain a binarized graph of the current image; performing non-linear filtration and morphological processing on the binarized graph of the current image, to facilitate detection of a target; and identifying the target by using an edge detection or convex hull detection algorithm, and if the target is detected, sending out an alarm to end a process, and if the target is not detected, updating the current image into a next frame of background image for image detection. The method provided by the present invention is capable of accurately detecting the foreign body and achieves a relatively low calculation amount.

An automatic threshold control device for a burst mode optical receiver is disclosed. The receiver includes a converter that converts a burst mode signal into a voltage signal and an automatic gain controller for automatically controlling a gain of the converter, independently generating a reset signal and applying it to the automatic threshold control device. The automatic threshold control device is adapted to detect a voltage level of an output signal from the converter. The device includes a peak detector that detects a peak level of the output signal from the converter in response to the reset signal, a bottom level detector that detects a bottom level of the output signal from the converter in response to the reset signal, a pair of resistors having their one sides connected respectively to the peak detector and bottom level detector and their other sides connected to each other, the resistors generating a reference voltage on the basis of voltages of the peak level and bottom level, and a capacitor for storing the reference voltage.

The invention discloses a text clustering method on the basis of an automatic threshold fish swarm algorithm. The text clustering method includes computing a similarity matrix of feature vectors of texts, acquiring an initial equivalent partitioning threshold of each text by a corresponding row of elements of the similarity matrix, performing initial equivalent partitioning for the texts and determining an initial clustering number and an initial clustering center; and adopting the artificial fish swarm algorithm in a combination manner, updating the state of each artificial fish according to global optimal information and local optimal information, searching a global optimal clustering center and clustering initial clustering results again. The text clustering method has the advantages that the initial clustering number and the initial clustering center are acquired by a process for automatically acquiring the thresholds, the global optimal clustering center is searched by the aid of the artificial fish swarm algorithm, accordingly, shortcomings that the traditional clustering method is sensitive to initial values and only relies on local data characteristics and the like are overcome, and the text clustering accuracy and the text clustering intelligence can be improved.

The invention discloses a method for automatically cutting a granular object in a digital image, belonging to the technical field of digital image processing. The method comprises the following steps of: firstly, separating an object from a background by applying an automatic threshold method by aiming at characteristics such as gray level, structural distribution, geometry and the like of the granular object in the digital image, particularly a microscopic image; then, calculating a gradient vector field of the object, and searching a key point in the gradient vector field, wherein the idealkey point has corresponding gradient vector distribution in eight neighborhoods, the gradient value of the key point is zero, and the acquired key point is used as the center of each granular object;next, defining a new effective energy function based on the gray level and a space position so as to calculate a direction gradient to replace the traditional gray level gradient; and finally, searching the boundary of the granular object by applying an active contour model. By using the method, the aggregated granular object can be accurately and effectively cut, particularly, a great number of adhered or overlapped micro-grains exist in a biomedical microscopic image, and therefore, help is provided for the image analysis and identification.

The invention provides a machine vision-based stainless steel soup ladle defect detection method. The machine vision-based stainless steel soup ladle defect detection method comprises the following steps: S1), acquiring a to-be-detected stainless steel soup ladle surface defect image; S2), sequentially performing graying, gray scale transformation and image smoothing pretreatment on the acquired surface defect image; S3), performing threshold segmentation on the pretreated image by an automatic threshold segmentation method to obtain a plurality of independent areas; S4), eliminating misjudgedpixel points and tolerable tiny defects through area characteristics and judging whether defects exist in the products or not; and S5), classifying the products with the defects through roundness characteristics and performing pixel area calculation and positioning on the defects in the image. By the method, the defect detection of the stainless steel soup ladle can be realized, the detection accurate rate of the stainless steel soup ladle product surface scratch defects is up to 100 percent, the integrated defect detection accurate rate is up to 96 percent or more, different types of defectsof the soup ladle can be detected pertinently, the detection efficiency is high, and the detection stability is achieved.

The invention aims at providing a satellite signal capturing system. The satellite signal capturing system comprises a PNGEN pseudo code generating module, a PN code double-port RAM, a CORACC relevant accumulation module, a DDC down-conversion module, a down-sampling module, a ping-pong RAM, an FFT computing module, an automatic threshold module, a peak detection module, an ACC accumulation module, an FFTCARCAL-parallel-carrier search result computing module, a capture judging module, a DATAPRO data processing module, an SCHCTL process control module and a tracking module. Data buffering is carried out on the output end of the PNGEN pseudo code generating module through the double-port RAM, a pseudo code is generated in the inside through a 100-MHz clock, and pseudo code data with the size equal to the capacity of the double-port RAM are generated every time. As improvement design is carried out on the satellite signal capturing system, signal transmission and an operation process are optimized, the occupancy of system resources in the satellite signal capturing process is reduced, delayed waiting is reduced, the operation speed is increased, and signal capturing accuracy and signal capturing stability are improved.