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Automatic Recognition Method for Optical Measuring Instruments Based on Machine Vision 被引量:2
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作者 宋乐 林玉池 郝立果 《Transactions of Tianjin University》 EI CAS 2008年第3期202-207,共6页
Based on a comprehensive study of various algorithms, the automatic recognition of traditional ocular optical measuring instruments is realized. Taking a universal tools microscope(UTM) lens view image as an example, ... Based on a comprehensive study of various algorithms, the automatic recognition of traditional ocular optical measuring instruments is realized. Taking a universal tools microscope(UTM) lens view image as an example, a 2-layer automatic recognition model for data reading is established after adopting a series of pre-processing algorithms. This model is an optimal combination of the correlation-based template matching method and a concurrent back propagation(BP) neural network. Multiple complementary feature extraction is used in generating the eigenvectors of the concurrent network. In order to improve fault-tolerance capacity, rotation invariant features based on Zernike moments are extracted from digit characters and a 4-dimensional group of the outline features is also obtained. Moreover, the operating time and reading accuracy can be adjusted dy-namically by setting the threshold value. The experimental result indicates that the newly developed algorithm has optimal recognition precision and working speed. The average reading ratio can achieve 97.23%. The recognition method can automatically obtain the results of optical measuring instruments rapidly and stably without modifying their original structure, which meets the application requirements. 展开更多
关键词 automatic recognition optical measuring instruments template matching neural network
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Method of Predicting Water Content in Crude Oil Based on Measuring Range Automatic Switching
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作者 陈祥光 朱文博 +1 位作者 赵军 任磊 《Journal of Beijing Institute of Technology》 EI CAS 2010年第1期87-91,共5页
Water content in output crude oil is hard to measure precisely because of wide range of dielectric coefficient of crude oil caused by injected dehydrating and demulsifying agents.The method to reduce measurement error... Water content in output crude oil is hard to measure precisely because of wide range of dielectric coefficient of crude oil caused by injected dehydrating and demulsifying agents.The method to reduce measurement error of water content in crude oil proposed in this paper is based on switching measuring ranges of on-line water content analyzer automatically.Measuring precision on data collected from oil field and analyzed by in-field operators can be impressively improved by using back propogation (BP) neural network to predict water content in output crude oil.Application results show that the difficulty in accurately measuring water-oil content ratio can be solved effectively through this combination of on-line measuring range automatic switching and real time prediction,as this method has been tested repeatedly on-site in oil fields with satisfactory prediction results. 展开更多
关键词 water content in crude oil prediction method BP network measuring range automatic switching
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AN AUTOMATIC HEAT FLUX-TEMPERATURE MEASURING SYSTEM AND ITS APPLICATION
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作者 Lu Shunchang Mao Fangguan Engineers, Naval Medical Research Institute, P. L. A., Shanghai 《China Ocean Engineering》 SCIE EI 1989年第3期375-382,共8页
An automatic heat flux-temperature measuring system can be used to measure local body heat flux, local skin temperature, body core temperature, and ambient temperature, as well as mean body heat flux, mean skin temper... An automatic heat flux-temperature measuring system can be used to measure local body heat flux, local skin temperature, body core temperature, and ambient temperature, as well as mean body heat flux, mean skin temperature, physiological shell thermal insulation and suit thermal insulation. This paper describes the measuring principle, hardware construction, software program and the application in thermal measurements on divers. 展开更多
关键词 AN automatic HEAT FLUX-TEMPERATURE measuring SYSTEM AND ITS APPLICATION HEAT BODY ITS
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High-precision automatic measurement of two-dimensional geometric features based on machine vision 被引量:6
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作者 何博侠 何勇 +1 位作者 薛蓉 杨洪锋 《Journal of Southeast University(English Edition)》 EI CAS 2012年第4期428-433,共6页
To realize high-precision automatic measurement of two-dimensional geometric features on parts, a cooperative measurement system based on machine vision is constructed. Its hardware structure, functional composition a... To realize high-precision automatic measurement of two-dimensional geometric features on parts, a cooperative measurement system based on machine vision is constructed. Its hardware structure, functional composition and working principle are introduced. The mapping relationship between the feature image coordinates and the measuring space coordinates is established. The method of measuring path planning of small field of view (FOV) images is proposed. With the cooperation of the panoramic image of the object to be measured, the small FOV images with high object plane resolution are acquired automatically. Then, the auxiliary measuring characteristics are constructed and the parameters of the features to be measured are automatically extracted. Experimental results show that the absolute value of relative error is less than 0. 03% when applying the cooperative measurement system to gauge the hole distance of 100 mm nominal size. When the object plane resolving power of the small FOV images is 16 times that of the large FOV image, the measurement accuracy of small FOV images is improved by 14 times compared with the large FOV image. It is suitable for high-precision automatic measurement of two-dimensional complex geometric features distributed on large scale parts. 展开更多
关键词 machine vision two-dimensional geometric features high-precision measurement automatic measurement
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Adjusting precipitation measurements from the TRwS204 automatic weighing gauge in the Qilian Mountains, China 被引量:5
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作者 ZHENG Qin CHEN Ren-sheng +9 位作者 HAN Chun-tan LIU Jun-feng SONG Yao-xuan LIU Zhang-wen YANG Yong WANG Lei WANG Xi-qiang LIU Xiao-jiao GUO Shu-hai LIU Guo-hua 《Journal of Mountain Science》 SCIE CSCD 2018年第11期2365-2377,共13页
With the popularity of the automatic precipitation gauges in national weather stations,testing their performance and adjusting their measurements are top priorities. Additionally,because different climatic conditions ... With the popularity of the automatic precipitation gauges in national weather stations,testing their performance and adjusting their measurements are top priorities. Additionally,because different climatic conditions may have different effects on the performance of the precipitation gauges, it is also necessary to test the gauges in different areas. This study mainly analyzed precipitation measurements from the single-Altershielded TRwS204 automatic weighing gauge(TRwS_(SA)) relative to the adjusted manual measurements(reference precipitation) from the Chinese standard precipitation gauge in a doublefence wind shield(CSPG_(DF)) in the Hulu watershed in the Qilian Mountains, China. The measurements were compared over the period from August 2014 to July2017, and the transfer function derived from the work by Kochendorfer et al.(2017 a) for correcting windinduced losses was applied to the TRwS_(SA) measurements. The results show that the average loss of TRwS_(SA) measurements relative to the reference precipitation decreased from 0.55 mm(10.7%) to 0.51 mm(9.9%) for rainfall events, from 0.35 mm(8.5%)to 0.22 mm(5.3%) for sleet events, and from 0.49 mm(18.9%) to 0.33 mm(12.7%) for snowfall events after adjustment. The uncorrected large biases of TRwS_(SA) measurements are considered to be mainly caused by specific errors of TRwS_(SA), different gauge orifice area and random errors. These types of errors must be considered when comparing precipitation measurements for different gauge types, especially in the mountains. 展开更多
关键词 TRwS204 automatic weighing gauge Chinese standard precipitation gauge Adjusting precipitation measurements Qilian Mountains
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An intelligent automatic correlation method of oilbearing strata based on pattern constraints:An example of accretionary stratigraphy of Shishen 100 block in Shinan Oilfield of Bohai Bay Basin,East China
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作者 WU Degang WU Shenghe +1 位作者 LIU Lei SUN Yide 《Petroleum Exploration and Development》 SCIE 2024年第1期180-192,共13页
Aiming at the problem that the data-driven automatic correlation methods which are difficult to adapt to the automatic correlation of oil-bearing strata with large changes in lateral sedimentary facies and strata thic... Aiming at the problem that the data-driven automatic correlation methods which are difficult to adapt to the automatic correlation of oil-bearing strata with large changes in lateral sedimentary facies and strata thickness,an intelligent automatic correlation method of oil-bearing strata based on pattern constraints is formed.We propose to introduce knowledge-driven in automatic correlation of oil-bearing strata,constraining the correlation process by stratigraphic sedimentary patterns and improving the similarity measuring machine and conditional constraint dynamic time warping algorithm to automate the correlation of marker layers and the interfaces of each stratum.The application in Shishen 100 block in the Shinan Oilfield of the Bohai Bay Basin shows that the coincidence rate of the marker layers identified by this method is over 95.00%,and the average coincidence rate of identified oil-bearing strata reaches 90.02% compared to artificial correlation results,which is about 17 percentage points higher than that of the existing automatic correlation methods.The accuracy of the automatic correlation of oil-bearing strata has been effectively improved. 展开更多
关键词 oil-bearing strata automatic correlation contrastive learning stratigraphic sedimentary pattern marker layer similarity measuring machine conditional constraint dynamic time warping algorithm
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Automatic Measurement of Fetal Abdominal Biometric Parameters—Feasibility on a Portable Ultrasound Device 被引量:1
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作者 Naiad Hossain Khan Eva Tegnander +4 位作者 Sigurd Storve Johan Morten Dreier Sturla Eik-Nes Hans Torp Gabriel Kiss 《Open Journal of Obstetrics and Gynecology》 2017年第8期922-936,共15页
An automatic method for measuring the fetal mean abdominal diameter (MAD) or abdominal circumference (AC) with ultrasound is proposed. From a correctly presented abdominal section suitable for MAD or AC measurement, t... An automatic method for measuring the fetal mean abdominal diameter (MAD) or abdominal circumference (AC) with ultrasound is proposed. From a correctly presented abdominal section suitable for MAD or AC measurement, the location of fetal abdomen is detected by image processing. Thereafter, an active contour model is converged along the abdominal boundary for measurement purposes. The validation data set contained 310 images of fetuses with gestational age (GA) from 14 to 41 weeks. The measurement success rate was 88.1%. By manually indicating the location of the abdomen, the success rate was further improved to 95.8% for the failed cases. The correlation between manual and automatic measurements was 0.95 and the intraclass correlation coefficient (ICC) was 0.976 (95% confidence interval (CI);0.969 - 0.981). The average method execution time was 0.3 s. The mean error was lower in young fetuses (0.4%) than in older fetuses (-2.1%). The proposed cross-platform method was implemented on a portable, low-cost ultrasound machine prototype targeted for low- and middle-income countries (LMIC);the results achieved were comparable to those of other state-of-the-art automatic methods. 展开更多
关键词 Portable ULTRASOUND Scanner automatic measurement Mean ABDOMINAL Diameter ABDOMINAL CIRCUMFERENCE PRENATAL ULTRASOUND ICT4D
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Automatic Monitoring System for 3-D Deformation of Crustal Fault Based on Laser and Machine Vision
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作者 Qingshan Wang Guoying Su +3 位作者 Qingzun Ma Haiquan Yin Zhihang Liu Chuanzhen Lv 《Instrumentation》 2024年第2期44-52,共9页
An automatic monitoring method of the 3-D deformation is presented for crustal fault based on laser and machine vision. The laser source and screen are independently set up in the headwall and footwall, the collimated... An automatic monitoring method of the 3-D deformation is presented for crustal fault based on laser and machine vision. The laser source and screen are independently set up in the headwall and footwall, the collimated laser beam creates a circular spot on the screen, meanwhile, the industrial camera captures the tiny deformation of the crustal fault by monitoring the change of the spot position. This method significantly reduces the cost of equipment and labor, provides daily sampling to ensure high continuity of data. A prototype of the automatic monitoring system is developed, and a repeatability test indicates that the error of spot jitter can be minimized by consecutive samples. Meanwhile, the environmental correction model is determined to ensure that environmental changes do not disturb the system. Furthermore, the automatic monitoring system has been applied at the deformation monitoring station(KJX02) of China Beishan underground research laboratory, where continuous deformation monitoring is underway. 展开更多
关键词 deformation measurement crustal fault automatic monitoring laser spot machine vision
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Automatic Detection and Measurement of Fetal Biparietal Diameter and Femur Length —Feasibility on a Portable Ultrasound Device
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作者 Naiad Hossain Khan Eva Tegnander +3 位作者 Johan Morten Dreier Sturla Eik-Nes Hans Torp Gabriel Kiss 《Open Journal of Obstetrics and Gynecology》 2017年第3期334-350,共17页
An automatic method able to recognize a presented section through the biparietal plane of the fetal head and a section through the fetal femur in ultrasound images is developed. Once the correct anatomical section for... An automatic method able to recognize a presented section through the biparietal plane of the fetal head and a section through the fetal femur in ultrasound images is developed. Once the correct anatomical section for measurement is identified by the machine, the placement of the measurement calipers is automatically determined by fitting an active contour model to the structure of interest. The fetal biparietal diameter (BPD) and femur length (FL) are then measured automatically. The validation data set contained 167 and 197 B-mode images for BPD and FL measurements, respectively. The images were acquired using 4 different ultrasound scanners, which resulted in varied image quality and gain settings. The mean gestational age (GA) of the fetuses was 19.4 weeks, range 16 to 41 weeks. A measurement success rate of 90% was achieved for both BPD and FL. The correlation coefficients between the manual and automatic measurements were 0.995 (BPD) and 0.967 (FL), mean errors were 0.5 mm (BPD) and -1.7 mm (FL) and error range with 95% confidence interval (CI) were ﹣3.8 - 4.8 mm (BPD) and ﹣11.4 - 8.1 mm (FL). The automatic measurement results were consistent in both high and low gain settings. The intraclass correlation coefficients between manual and automatic measurements were 0.995 (95% CI;0.981 - 0.999) for BPD in high gain, 1.0 (95% CI;0.998 - 1.0) for BPD in low gain, 0.998 (95% CI;0.991 - 0.999) for FL in high gain and 0.999 (95% CI;0.996 - 1.0) for FL in low gain settings. The method was implemented on a prototype, portable ultrasound machine designed to be used in low- and middle-income countries (LMIC). The overall performance of the method supports our hypothesis that automated methods can be used and are beneficial in a clinical setting. 展开更多
关键词 FETAL DATING Biparietal DIAMETER FEMUR Length PORTABLE Ultrasound Machine automatic measurement
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Automatic measurement of air-pressure sensor based on two-pressure control instrument
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作者 丁红英 赵湛 +1 位作者 轩运动 方震 《Journal of Measurement Science and Instrumentation》 CAS 2013年第1期6-9,共4页
To measure the performance of high precision air-pressure sensors in below normal pressure,an automatic measurement instrument has been designed and implemented.It can simulate environment of low pressure from 300hPa ... To measure the performance of high precision air-pressure sensors in below normal pressure,an automatic measurement instrument has been designed and implemented.It can simulate environment of low pressure from 300hPa to 1 000hPa with high accuracy by proportional-integral-derivative(PID)control quickly,and it can also generate various relative humidity by two-pressure control.The results show that this instrument can reach controlled pressure quickly.And it works well with the minimum average pressure difference,and the fluctuation is±0.02hPa at 500hPa.And it can keep in a stable status for a long time.It works well in performance testing of pressure sensors.The structure of the system is simple,takes small investment,and can be operated conveniently. 展开更多
关键词 automatic measurement two-pressure pressure sensor proportional integral derivative(PID)control
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Design of a Modularized Automatic Measurement and Control System for LaserInduced Breakdown Spectrometer
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作者 丁宇 田地 +2 位作者 陈飞鹏 乔淑君 杨光 《Journal of Donghua University(English Edition)》 EI CAS 2014年第4期406-410,共5页
In order to improve the compatibility of laser-induced breakdown spectroscopy( LIBS) instrument for different types of parts and optimize the analysis and testing processes,a modularized automatic measurement and cont... In order to improve the compatibility of laser-induced breakdown spectroscopy( LIBS) instrument for different types of parts and optimize the analysis and testing processes,a modularized automatic measurement and control system was developed. Based on the characteristics of each LIBS component, the following development steps have been performed:( 1) a summary of characteristic parameters of the component are established;( 2) the integration mechanism of multiple electrical interfaces is designed;( 3) the component control instruction library is developed. The experimental results indicate that the measurement and control system is compatible with most LIBS parts in the market.Spectrometer and laser can be compatible with at least three different types of parts. In addition,a multilayer iterative testing process is designed to improve the efficiency of optimization process of LIBS parameters. The experimental results have shown that the automatic optimization of the delay time compared to the manual testing provides significant gain in testing efficiency. The range of delay time in the experiments is 1. 28 to 10. 28 μs and the step value is 1,0. 5,0. 2 and 0. 1 μs. The gain in testing efficiency has been found to be increased by 73. 76%,75. 93%,78. 81% and 80. 42%,respectively. 展开更多
关键词 automatic control technique laser-induced breakdown spectroscopy(LIBS) measurement and control system(MCS) COMPONENT
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Measurement of Stone Diameter with Three Sizes of Automatically Fixating Stone Baskets
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作者 Jens Cordes Felix Nguyen +1 位作者 Wolfgang Pinkowski Dieter Jocham 《Open Journal of Urology》 2013年第2期58-61,共4页
Background: Complications after endoscopic retrieval of kidney and ureter stones are obviously related to the size of the stones as well as the experience of the surgeon and other factors. During the procedure it is s... Background: Complications after endoscopic retrieval of kidney and ureter stones are obviously related to the size of the stones as well as the experience of the surgeon and other factors. During the procedure it is sometimes difficult for surgeons to estimate stone size and therefore give prognostic advises. The visual perception of the stone size depends on the shape, colour, distance to the renoscope and dilatation of the ureter. This is the so-called binding problem, because shape, color and direction of motion are processed separately by different population of optical neurons. In order to establish a better prognostic rational especially for less experienced surgeons, we established an intra operative semi-quantitative measurement of the stone size supported by a stone basket. Materials and Methods: We modified the tipped, nitinol stone baskets from the company Urotech with diameters of 2.5, 3.0 and 4 FR. The handle of this basket has a spring mechanism, which automatically closes the basket and provides a predefined fixation force of the stones within the basket. On the handle we established a non-linear scale in mm by grabbing standardized balls or standardized screws. Result: The scales are nonlinear because of the nonlinear relation between the diameter of the stone and the distance of the slider. Also the scales differ in between the basket size, because of the different strain conditions due to the different wire sizes and materials or the spring and basket. Conclusion: This scale could be an important orientation for a surgeon during endourological procedures to estimate stone sizes. After further clinical experience a semi-quantitative visualization like green, yellow and red colors could help to predict potential complications due to large stone sizes. Finally it could bevery interesting for other disciplines like gastroenterology. 展开更多
关键词 STONE Basket automaticALLY Fixating STONE Basket measurement of STONE SIZE
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Fabrication of automatic switch for AC-DC completely automated measurement system at NIS
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作者 M Helmy A Raouf Rasha S M Ali 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2017年第1期27-31,共5页
A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed relays.This new switch is introduced to establish a fully automated system for AC-DC measur... A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed relays.This new switch is introduced to establish a fully automated system for AC-DC measurements through ACDC transfer standards for the first time at the National Institute for standards(N IS)in Egypt.The implemented circuit of theautomatic AC-DC switch and its protection are presented in details.An AC voltage source is calibrated against DC voltagesource by using the demonstrated automatic switch as an application The calibrated voltage ranges are2V,6V,20V and60V as examples.The uncertainty budget is also evaluated for the calibrated values. 展开更多
关键词 AC voltage measurement AC-DC transfer standard automatic switching system UNCERTAINTY
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Study on Factors Influencing the Quality of Automatic Monitoring Data of Pollution Sources and Technical Assurance Measures
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作者 Hanju BAO Yun WU Chengxin PAN 《Meteorological and Environmental Research》 CAS 2021年第6期53-58,共6页
Automatic monitoring data of pollution sources is an important basis for environmental supervision and management.At present,it is difficult to guarantee the quality of automatic monitoring data of pollution sources,a... Automatic monitoring data of pollution sources is an important basis for environmental supervision and management.At present,it is difficult to guarantee the quality of automatic monitoring data of pollution sources,and it is difficult to play the role of the monitoring data.In response to this problem,the factors influencing the quality of automatic monitoring data of pollution sources were analyzed in detail,and technical assurance measures for the quality of automatic monitoring data of pollution sources in Shandong Province were studied.Besides,the dynamic management and control idea of automatic monitoring of pollution sources was proposed,and specific technical measures were analyzed from five aspects of standardizing automatic monitoring equipment of pollution sources,improving the data collection and transmission system,establishing a mechanism for reporting operating status information of monitoring equipment,setting alarm rules and alarm processing procedures,and statistically analyzing the operating status of the equipment.Practice has proved that the dynamic management and control system can effectively ensure the quality of automatic monitoring data of pollution sources. 展开更多
关键词 automatic monitoring Quality assurance Technical measures Dynamic management and control
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Design of mobile sensing system for automatical measurement
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作者 ZHU Jun-jiang HE Ling-song 《Journal of Measurement Science and Instrumentation》 CAS 2014年第2期68-75,共8页
Based on mobile devices as a solution for measurement faces interesting challenges, which involve poor human- computer interaction and limited computer capability. In this paper, we present the mobile sensing system ... Based on mobile devices as a solution for measurement faces interesting challenges, which involve poor human- computer interaction and limited computer capability. In this paper, we present the mobile sensing system (MSS) with func- tions of constructing, configuring and implementing measurement applications. MSS consists of a mobile device and a sensor probe, In the mobile device we install a pocket virtual instrument platform (PVIP), which has object-oriented software ar- chitecture and can be configured through extensible markup language (XML) files. And these configuration files can be written to the probe. Therefore, the probe can produce the measurement of APP in the mobile device. This infrastructure has been illustrated by a sound signal acquisition task and a flexible force measurement task which are finished with an android smartphone and a probe. These examples suggest that MSS is reconfigurable, highly automatical and flexible. 展开更多
关键词 mobile sensing system (MSS) automatical measurement RECONFIGURABILITY extensible markup language(XML) pocket virtual instrument platform (PVIP)
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Measuring the Condition of Parking Lot by Image Processing
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作者 吴大勇 魏平 侯朝桢 《Journal of Beijing Institute of Technology》 EI CAS 1999年第3期232-237,共6页
Aim To study the parking management in the condition of vehicles' increasing. Methods The methods of pattern recognition and image processing were used to analyze the eigenvalues of parking lot images. Results ... Aim To study the parking management in the condition of vehicles' increasing. Methods The methods of pattern recognition and image processing were used to analyze the eigenvalues of parking lot images. Results The automatic identification of every parking place in the parking plot was realized. The automatic measuring of parked vehicle count and parking lot utilization was completed. Conclusion It can complete the real time recognition, and has some practicabilities. 展开更多
关键词 automatic measuring digital image processing pattern recognition
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Machine Learning of Weather Forecasting Rules from Large Meteorological Data Bases 被引量:1
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作者 Honghua DaiDepartment of Computer Science,Monash University,Australia,dai@ brucc.cs.monash.edu.au 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1996年第4期471-488,共18页
Discovery of useful forecasting rules from observational weather data is an outstanding interesting topic.The traditional methods of acquiring forecasting knowledge are manual analysis and investigation performed by h... Discovery of useful forecasting rules from observational weather data is an outstanding interesting topic.The traditional methods of acquiring forecasting knowledge are manual analysis and investigation performed by human scientists.This paper presents the experimental results of an automatic machine learning system which derives forecasting rules from real observational data.We tested the system on the two large real data sets from the areas of centra! China and Victoria of Australia.The experimental results show that the forecasting rules discovered by the system are very competitive to human experts.The forecasting accuracy rates are 86.4% and 78% of the two data sets respectively 展开更多
关键词 Weather forecasting Machine learning Machine discovery Meteorological expert system Meteorological knowledge processing automatic forecasting
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Automatic Partition of Chinese Sentence Group 被引量:3
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作者 陈怡疆 史晓东 周昌乐 《Journal of Donghua University(English Edition)》 EI CAS 2010年第2期177-180,共4页
Automatic partition of Chinese sentence group is very important to the statistical machine translation system based on discourse. This paper presents an approach to this issue: first, each sentence in a discourse is ... Automatic partition of Chinese sentence group is very important to the statistical machine translation system based on discourse. This paper presents an approach to this issue: first, each sentence in a discourse is expressed as a feature vector; second, a special hierarchical clustering algorithm is applied to present a discourse as a sentence group tree. In this paper, local reoccurrence measure is proposed to the selection of key phras and the evaluation of the weight of key phrases. Experimental results show our approach promising. 展开更多
关键词 sentence group automatic partition of sentence group sentence group tree local reoccurrence measure
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Adaptive load forecasting of the Hellenic electric grid 被引量:1
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作者 S.Sp.PAPPAS L.EKONOMOU +2 位作者 V.C.MOUSSAS P.KARAMPELAS S.K.KATSIKAS 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第12期1724-1730,共7页
Designers are required to plan for future expansion and also to estimate the grid's future utilization. This means that an effective modeling and forecasting technique, which will use efficiently the information c... Designers are required to plan for future expansion and also to estimate the grid's future utilization. This means that an effective modeling and forecasting technique, which will use efficiently the information contained in the available data, is required, so that important data properties can be extracted and projected into the future. This study proposes an adaptive method based on the multi-model partitioning algorithm (MMPA), for short-term electricity load forecasting using real data. The grid's utilization is initially modeled using a multiplicative seasonal ARIMA (autoregressive integrated moving average) model. The proposed method uses past data to learn and model the normal periodic behavior of the electric grid. Either ARMA (autoregressive moving average) or state-space models can be used for the load pattern modeling. Load anomalies such as unexpected peaks that may appear during the summer or unexpected faults (blackouts) are also modeled. If the load pattern does not match the normal be-havior of the load, an anomaly is detected and, furthermore, when the pattern matches a known case of anomaly, the type of anomaly is identified. Real data were used and real cases were tested based on the measurement loads of the Hellenic Public Power Cooperation S.A., Athens, Greece. The applied adaptive multi-model filtering algorithm identifies successfully both normal periodic behavior and any unusual activity of the electric grid. The performance of the proposed method is also compared to that produced by the ARIMA model. 展开更多
关键词 Adaptive multi-model filtering ARIMA Load forecasting measurements Kalman filter Order selection SEASONALVARIATION Parameter estimation
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An Automatic Synchronization Method for Distributed Power Electronics System
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作者 Cheng Zhang Chi Sun Sheng Ai 《Energy and Power Engineering》 2013年第3期24-27,共4页
Currently, the high-speed serial fiber-optic ring net communication is a main method for performing the distributed control network topology and control mode. Because of a network transmission delay inherent in the to... Currently, the high-speed serial fiber-optic ring net communication is a main method for performing the distributed control network topology and control mode. Because of a network transmission delay inherent in the topology, synchronization between nodes has become a critical issue which needs to be studied. The existing synchronization methods largely depend on the complex communication protocol. Therefore, this paper has proposed a method of automatic measurement and compensation of synchronization delay, and analyzed its operating principle and implementation procedure in detail. The results obtained from the experiments prove the proposed method to be correct, effective and practicable. 展开更多
关键词 Power ELECTRONICS CONVERTER System(PECS) Distributed Control DELAY automatic measurement SYNCHRONIZATION
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