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Study and Implementation of Web Mining Classification Algorithm Based on Building Tree of Detection Class Threshold
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作者 陈俊杰 宋瀚涛 陆玉昌 《Journal of Beijing Institute of Technology》 EI CAS 2005年第2期126-129,共4页
A new classification algorithm for web mining is proposed on the basis of general classification algorithm for data mining in order to implement personalized information services. The building tree method of detecting... A new classification algorithm for web mining is proposed on the basis of general classification algorithm for data mining in order to implement personalized information services. The building tree method of detecting class threshold is used for construction of decision tree according to the concept of user expectation so as to find classification rules in different layers. Compared with the traditional C4.5 algorithm, the disadvantage of excessive adaptation in C4.5 has been improved so that classification results not only have much higher accuracy but also statistic meaning. 展开更多
关键词 data mining classification algorithm class threshold induced concept
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Statistical Tools for Estimation of Threshold Values at Data Classification Task Solution
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作者 V. V. Glinskiy L. K. Serga +1 位作者 E. Yu. Chemezova K. A. Zaykov 《Open Journal of Statistics》 2014年第9期736-741,共6页
The paper contains a summary of some results of original research total aggregates. The main idea is determining the boundaries of the groups for classification of fuzzy and threshold aggregates using the method of de... The paper contains a summary of some results of original research total aggregates. The main idea is determining the boundaries of the groups for classification of fuzzy and threshold aggregates using the method of decomposing a mixture of probability distributions. The article presents the experience of partitions of a real aggregate as a finite mixture of probability distributions on private aggregates. Threshold value defined by the boundaries of private aggregates, will match the value of the phenomenon at the intersection of the curves of probability distributions, which extracted from the mixture. The proposed scheme of identification threshold aggregates has found practical application in the research of aggregate of Russian employees by level of payroll and establishing the optimal minimum value monthly wage. The official data of the Federal State Statistics Service were used. 展开更多
关键词 classification threshold AGGREGATE MIXTURE of PROBABILITY DISTRIBUTIONS
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The Vegetation Classification of the Return Farmland to Pasture or Forest Region in Shaanxi-Gansu-Ningxia Based on SPOT/VEGETATION Data 被引量:9
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作者 李剑萍 官景得 +2 位作者 韩颖娟 王石立 马玉平 《Agricultural Science & Technology》 CAS 2009年第5期179-183,共5页
In order to assess the climatical and ecological effect which returned the farmland to pasture or forest, the vegetation and crop in Northwest China with suitable threshold value were classified in this experiment by ... In order to assess the climatical and ecological effect which returned the farmland to pasture or forest, the vegetation and crop in Northwest China with suitable threshold value were classified in this experiment by using multi-temporal SPOT/VEGETATION dada and combing supervised classification with unsupervised classification. Compared with the data from Statistical Department and actual investigation, the precision of the classified result was above 85%. 展开更多
关键词 SPOT/VEGETATION MULTI-TEMPORAL threshold value classification
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Penile sensory thresholds in subtypes of premature ejaculation: implications of comorbid erectile dysfunction 被引量:12
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作者 Xiang Chen Fei-Xiang Wang +2 位作者 Chao HU Nian-Qin Yang Ji-Can Dai 《Asian Journal of Andrology》 SCIE CAS CSCD 2018年第4期330-335,共6页
Penile hypersensitivity plays an important role in premature ejaculation (PE), but differences in penile sensitivity among subtypes of PE are unknown. Therefore, we compared penile sensory thresholds in PE subtypes ... Penile hypersensitivity plays an important role in premature ejaculation (PE), but differences in penile sensitivity among subtypes of PE are unknown. Therefore, we compared penile sensory thresholds in PE subtypes of lifelong and acquired PE, PE with and without erectile dysfunction (ED), PE with an intravaginal ejaculation latency time 〈1 min and 〉1 min, and PE with and without orgasmic pleasure perceptual dysfunction. During August 2014 to January 2016, 136 patients with PE were included. Penile warm, cold, and vibratory thresholds were measured. Data of clinical characteristics, sexual life, Premature Ejaculation Diagnostic Tool (PEDT) score, and the 5-item version of the International Index of Erectile Function (IIEF-5) score were collected. Vibratory thresholds of the PE with ED group were higher in the right coronal sulcus (median amplitude: 4.92 vs 3.65 μm, P= 0.02) and the right penile shaft (median amplitude: 3.87 vs 3.30 μm, P = 0.03), while differences in penile sensory thresholds between other subtypes were not significant. The median PEDT score was lower in the PE without ED group (12 vs 14, P 〈 0.001). The IIEF-5 and PEDT scores were negatively correlated (r = -0.29, P 〈 0.001). Patients with orgasmic pleasure perceptual dysfunction had a lower median IIEF-5 score (20 vs 21, P = 0.02). Patients with PE and ED had lower penile sensitivity, and ED was associated with more severe symptoms and weaker orgasmic pleasure perception. In men with PE, management of comorbid ED is necessary. In case of side effects in erectile function, topical anesthetics should be cautiously used in men with PE and ED. 展开更多
关键词 classification erectile dysfunction penile sensitivity PENIS premature ejaculation sensory thresholds
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A classification method of building structures based on multi-feature fusion of UAV remote sensing images
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作者 Haoguo Du Yanbo Cao +6 位作者 Fanghao Zhang Jiangli Lv Shurong Deng Yongkun Lu Shifang He Yuanshuo Zhang Qinkun Yu 《Earthquake Research Advances》 CSCD 2021年第4期38-47,共10页
In order to improve the accuracy of building structure identification using remote sensing images,a building structure classification method based on multi-feature fusion of UAV remote sensing image is proposed in thi... In order to improve the accuracy of building structure identification using remote sensing images,a building structure classification method based on multi-feature fusion of UAV remote sensing image is proposed in this paper.Three identification approaches of remote sensing images are integrated in this method:object-oriented,texture feature,and digital elevation based on DSM and DEM.So RGB threshold classification method is used to classify the identification results.The accuracy of building structure classification based on each feature and the multi-feature fusion are compared and analyzed.The results show that the building structure classification method is feasible and can accurately identify the structures in large-area remote sensing images. 展开更多
关键词 Remote sensing image Building structure classification Multi-feature fusion Object-oriented classification method Texture feature classification method DSM and DEM elevation classification method RGB threshold classification method
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A Semi-Vectorial Hybrid Morphological Segmentation of Multicomponent Images Based on Multithreshold Analysis of Multidimensional Compact Histogram 被引量:1
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作者 Adles Kouassi Sié Ouattara +2 位作者 Jean-Claude Okaingni Wognin J. Vangah Alain Clement 《Open Journal of Applied Sciences》 2017年第11期597-610,共14页
In this work, we propose an original approach of semi-vectorial hybrid morphological segmentation for multicomponent images or multidimensional data by analyzing compact multidimensional histograms based on different ... In this work, we propose an original approach of semi-vectorial hybrid morphological segmentation for multicomponent images or multidimensional data by analyzing compact multidimensional histograms based on different orders. Its principle consists first of segment marginally each component of the multicomponent image into different numbers of classes fixed at K. The segmentation of each component of the image uses a scalar segmentation strategy by histogram analysis;we mainly count the methods by searching for peaks or modes of the histogram and those based on a multi-thresholding of the histogram. It is the latter that we have used in this paper, it relies particularly on the multi-thresholding method of OTSU. Then, in the case where i) each component of the image admits exactly K classes, K vector thresholds are constructed by an optimal pairing of which each component of the vector thresholds are those resulting from the marginal segmentations. In addition, the multidimensional compact histogram of the multicomponent image is computed and the attribute tuples or ‘colors’ of the histogram are ordered relative to the threshold vectors to produce (K + 1) intervals in the partial order giving rise to a segmentation of the multidimensional histogram into K classes. The remaining colors of the histogram are assigned to the closest class relative to their center of gravity. ii) In the contrary case, a vectorial spatial matching between the classes of the scalar components of the image is produced to obtain an over-segmentation, then an interclass fusion is performed to obtain a maximum of K classes. Indeed, the relevance of our segmentation method has been highlighted in relation to other methods, such as K-means, using unsupervised and supervised quantitative segmentation evaluation criteria. So the robustness of our method relatively to noise has been tested. 展开更多
关键词 MORPHOLOGICAL SEGMENTATION Vectorial Orders Semi-Vectorial SEGMENTATION MULTIDIMENSIONAL COMPACT HISTOGRAM Multi-thresholds Fusion Inter-Class classification
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利用红外特征和Softmax回归识别绝缘子污秽等级 被引量:11
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作者 付鹏 姚建刚 龚磊 《计算机工程与应用》 CSCD 北大核心 2015年第13期181-185,共5页
提出了一种红外图像特征与Softmax回归相结合的方法识别绝缘子污秽等级。通过对红外图像的灰度化、图像滤波、二值化、盘面分割、半盘面提取等预处理过程,获取单个绝缘子半盘面区域。设计了以环境温度、绝缘子背景图像的平均灰度、绝缘... 提出了一种红外图像特征与Softmax回归相结合的方法识别绝缘子污秽等级。通过对红外图像的灰度化、图像滤波、二值化、盘面分割、半盘面提取等预处理过程,获取单个绝缘子半盘面区域。设计了以环境温度、绝缘子背景图像的平均灰度、绝缘子盘面区域的平均灰度、绝缘子盘面灰度分布的方差值、灰度熵和环境湿度共6个反映污秽等级的特征集的基于Softmax回归多值分类模型识别绝缘子污秽等级。引入概率阈值从问题源头出发,解决了拍摄时所产生的无效绝缘子红外图像对污秽等级分类的影响。实验结果表明所选取的特征集和绝缘子污秽识别模型高效且可行。 展开更多
关键词 绝缘子 红外热像 多元分类 Softmax回归 概率阈值
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Assessment of typhoon storm surge disaster scale based on expansion model 被引量:1
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作者 Guilin LIU Xiuxiu NONG +3 位作者 Yi KOU Fang WU Daniel ZHAO Zongbing YU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第2期518-531,共14页
The South China Sea suffers strongly from the typhoon storm surge disasters in China,and its northern coastal areas are facing severe risks.Therefore,it is necessary and urgent to establish an assessment system for ra... The South China Sea suffers strongly from the typhoon storm surge disasters in China,and its northern coastal areas are facing severe risks.Therefore,it is necessary and urgent to establish an assessment system for rating typhoon storm surge disaster.We constructed an effective and reliable rating assessment system for typhoon storm surge disaster based on the theories of over-threshold,distribution function family,and composite extreme value.The over-threshold sample was used as the basis of data analysis,the composite extreme value expansion model was used to derive the design water increment,and then the disaster level was delineated based on the return period level.The results of the extreme value model comparison show that the Weibull-Pareto distribution is more suitable than the classical extreme value distribution for fitting the over-threshold samples.The results of the return period projection are relatively stable based on different analysis samples.Taking the 10 typhoon storm surges as examples,they caused landfall in the Guangdong area in the past 10 years.The results of the assessment ranking indicate that the risk levels based on the return period levels obtained from different distributions are generally consistent.When classifying low-risk areas,the classification criteria of the State Oceanic Administration,China(SOA,2012)are more conservative.In the high-risk areas,the results of the assessment ranking based on return period are more consistent with those of the SOA. 展开更多
关键词 risk classification South China Sea typhoon storm surge extreme value expansion over threshold sampling
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Tasks and Priorities for Comprehensively Deepening Reform of China’s State Sector of Economy 被引量:1
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作者 黄群慧 《China Economist》 2015年第6期4-14,共11页
The Third Plenary Session of the 18th CPC Central Committee ushered in a new chapter of China's comprehensive deepening of reform. The basic objective of comprehensively deepening reform of the state sector of econom... The Third Plenary Session of the 18th CPC Central Committee ushered in a new chapter of China's comprehensive deepening of reform. The basic objective of comprehensively deepening reform of the state sector of economy in the new chapter is to fully integrate this sector with a sophisticated market economic system with the market playing the decisive role in resource allocation. In order to achieve this objective, China is confronted with the four major priorities of adjusting the functions and layout of the state sector of economy according to national mandates, expediting the mixed ownership reform, creating a classified and multi- tiered new system for the administration of the sector, and developing a modern corporate system for SOEs to ensure an efficient micro-level governance mechanism for the sector. (1) The functions of the different types of SOEs should be accurately defined and SOEs should be divided into the three types of public policy SOEs, functional SOEs, and commercial SOEs. This classification forms the premises for reforming the state sector of economy. Based on the functions of the three types of SOEs, the directions and emphases for strategic adjustment should differ as well. (2) The mixed ownership reform should adhere to the methodological principles of combining top-down and bottom-up approaches, implementing pilot programs, and promoting coordinated progress. Practical implementation should ensure fair and standard reform procedures, reform programs consistent with laws and regulations, open and fair equity transfers, as well as fair and transparent internal distributions. The mixed ownership reform of SOEs should introduce the employee stock ownership system and adhere to the principles of compatible incentives, shared growth, and long-term development. Monopolistic sectors should be transformed into competitive market structures to create conditions for the implementation of mixed ownership for SOEs. (3) The new system for the administration of the state sector of economy should comprise three hierarchies: the Commission for the Administration of State Economy at the top level, state capital operation companies or state capital investment companies at the intermediate level and general for-profit enterprises at the bottom level, which administer public policy, functional SOEs, and commercial SOEs respectively. (4) Under the new system for the administration of the state sector of economy characterized by the three hierarchies and categories, the key for perfecting the modern corporate system of SOEs is to establish a differentiated, classified governance mechanism, i.e., different corporate governance mechanisms should be created for SOEs of different functions and roles. 展开更多
关键词 state sector of economy comprehensively deepening reform classification offunctions strategic adjustment mixed ownership reform administrative system for the statesector of economy classified governance
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Noise wavelet-suppressing on electric signals in meso-spray process of pulse MIG welding of aluminum
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作者 杨立军 孙贵铮 李桓 《China Welding》 EI CAS 2010年第2期65-69,共5页
An analysis with Fourier series on electric signals of meso-spray process of pulse MIG welding of aluminum shows many harmonic waves of different frequency in the signals, including the inherent high, low frequency el... An analysis with Fourier series on electric signals of meso-spray process of pulse MIG welding of aluminum shows many harmonic waves of different frequency in the signals, including the inherent high, low frequency elementary waves of short circuit and the harmonic waves from pulse current besides the noise signals of high frequency. The wavelet filtering with adjustable threshold is applied to study and handle the electric signals from meso-spray process of pulse MIG welding of aluminum, displaying a good solution on suppressing the noise in the signals. 展开更多
关键词 pulse MIG welding meso-spray ALUMINUM WAVELET adjustable threshold
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Ultrafast Response and Threshold Adjustable Intelligent Thermoelectric Systems for Next‑Generation Self‑Powered Remote IoT Fire Warning
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作者 Zhaofu Ding Gang Li +5 位作者 Yejun Wang Chunyu Du Zhenqiang Ye Lirong Liang Long‑Cheng Tang Guangming Chen 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第11期413-428,共16页
Fire warning is vital to human life,economy and ecology.However,the development of effective warning systems faces great challenges of fast response,adjustable threshold and remote detecting.Here,we propose an intelli... Fire warning is vital to human life,economy and ecology.However,the development of effective warning systems faces great challenges of fast response,adjustable threshold and remote detecting.Here,we propose an intelligent self-powered remote IoT fire warning system,by employing single-walled carbon nanotube/titanium carbide thermoelectric composite films.The flexible films,prepared by a convenient solution mixing,display p-type characteristic with excellent high-temperature stability,flame retardancy and TE(power factor of 239.7±15.8μW m^(-1) K^(-2))performances.The comprehensive morphology and structural analyses shed light on the underlying mechanisms.And the assembled TE devices(TEDs)exhibit fast fire warning with adjustable warning threshold voltages(1–10 mV).Excitingly,an ultrafast fire warning response time of~0.1 s at 1 mV threshold voltage is achieved,rivaling many state-of-the-art systems.Furthermore,TE fire warning systems reveal outstanding stability after 50 repeated cycles and desired durability even undergoing 180 days of air exposure.Finally,a TED-based wireless intelligent fire warning system has been developed by coupling an amplifier,analogto-digital converter and Bluetooth module.By combining TE characteristics,high-temperature stability and flame retardancy with wireless IoT signal transmission,TE-based hybrid system developed here is promising for next-generation self-powered remote IoT fire warning applications. 展开更多
关键词 THERMOELECTRIC SELF-POWERED IoT fire warning Ultrafast response threshold adjustable
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Analysis of Characteristics of Lightning and Atmospheric Electric Field in Nanchang County
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作者 Landi ZHONG Lei HU 《Meteorological and Environmental Research》 CAS 2020年第1期1-6,共6页
Based on ground observation,lightning locator and atmospheric electric field instrument data,the characteristics of lightning and atmospheric electric field in Nanchang County were analyzed. The warning effect of the ... Based on ground observation,lightning locator and atmospheric electric field instrument data,the characteristics of lightning and atmospheric electric field in Nanchang County were analyzed. The warning effect of the atmospheric electric field instruments on lightning was studied,and the threshold of some atmospheric electric field instruments was adjusted according to the expectation of the warning accuracy rate. In Nanchang County,the annual number of thunderstorm days averaged 48. 6. Lightning mainly occurred from March to August,with a maximum of 8. 8 d in August. The lightning areas were mainly concentrated in the south,followed by the north,and the frequency of lightning in the middle was relatively low. The diurnal variation of lightning was obvious,and lightning happened most frequently from afternoon to evening. Five atmospheric electric field instruments were set up according to the lightning areas of Nanchang County. The average electric field intensity on a sunny day was 0. 06,0. 05,0. 16,0. 07,and 0. 17 kV/m respectively,with certain seasonal variations. The field intensity in June was the lowest in the whole year. The atmospheric electric field on a sunny day also had obvious diurnal variation characteristics,generally presenting the characteristics of double peaks and double valleys. The first peak of atmospheric electric field intensity appeared one hour later than that of relative humidity,and then the change trends were relatively consistent. After the adjustment,the warning accuracy rate of the atmospheric electric field instruments was greatly improved to meet the expectation. 展开更多
关键词 LIGHTNING CHARACTERISTICS ATMOSPHERIC electric field adjustment of WARNING threshold Nanchang COUNTY
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Differential pressure difference based altitude control of a stratospheric satellite
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作者 陈丽 WANG Xiaoliang 《High Technology Letters》 EI CAS 2024年第1期1-12,共12页
An autonomous altitude adjustment system for a stratospheric satellite(StratoSat)platform is proposed.This platform consists of a helium balloon,a ballonet,and a two-way blower.The helium balloon generates lift to bal... An autonomous altitude adjustment system for a stratospheric satellite(StratoSat)platform is proposed.This platform consists of a helium balloon,a ballonet,and a two-way blower.The helium balloon generates lift to balance the platform gravity.The two-way blower inflates and deflates the ballonet to regulate the buoyancy.Altitude adjustment is achieved by tracking the differential pressure difference(DPD),and a threshold switching strategy is used to achieve blower flow control.The vertical acceleration regulation ability is decided not only by the blower flow rate,but also by the designed margin of pressure difference(MPD).Pressure difference is a slow-varying variable compared with altitude,and it is adopted as the control variable.The response speed of the actuator to disturbance can be delayed,and the overshoot caused by the large inertia of the platform is inhibited.This method can maintain a high tracking accuracy and reduce the complexity of model calculation,thus improving the robustness of controller design. 展开更多
关键词 stratospheric satellite(StratoSat) differential pressure difference(DPD) altitude adjustment threshold switching strategy margin of pressure difference(MPD)
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TOFD图像中焊缝埋藏缺陷的智能评定与分级
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作者 余焕伟 任绪凯 +2 位作者 廖晓平 欧阳星峰 杜锡勇 《中国特种设备安全》 2024年第3期88-94,共7页
TOFD检测中缺陷的评定与分级主要依靠人工进行,需要消耗大量的精力和时间,而且还存在误判的可能性。针对该问题,本文提出一套不依赖人工干预的缺陷自动评定与质量分级方法,包括TOFD图像分区与标定、灵敏度评价、缺陷区域分割、评定与分... TOFD检测中缺陷的评定与分级主要依靠人工进行,需要消耗大量的精力和时间,而且还存在误判的可能性。针对该问题,本文提出一套不依赖人工干预的缺陷自动评定与质量分级方法,包括TOFD图像分区与标定、灵敏度评价、缺陷区域分割、评定与分级。试验结果表明,本文方法与传统人工方法相比,全程无须人工干预,能显著提高分析评定人员的工作效率,特别适合大型特种设备制造及安装过程中批量化TOFD图像的缺陷评定与质量分级。 展开更多
关键词 衍射时差超声检测 焊缝埋藏缺陷 评定与分级 阈值分割
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AUTOMATIC MULTILEVEL THRESHOLDING METHOD BASED ON MAXIMUM ENTROPY 被引量:2
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作者 曹力 史忠科 郑家伟 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第4期335-338,共4页
In the multilevel thresholding segmentation of the image, the classification number is always given by the supervisor. To solve this problem, a fast multilevel thresholding algorithm considering both the threshold val... In the multilevel thresholding segmentation of the image, the classification number is always given by the supervisor. To solve this problem, a fast multilevel thresholding algorithm considering both the threshold value and the classification number is proposed based on the maximum entropy, and the self-adaptive criterion of the classification number is given. The algorithm can obtain thresholds and automatically decide the classification number. Experimental results show that the algorithm is effective. 展开更多
关键词 multilevel thresholding maximum entropy classification number nonparametric method
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Multi-class classification method for strip steel surface defects based on support vector machine with adjustable hyper-sphere 被引量:2
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作者 Mao-xiang Chu Xiao-ping Liu +1 位作者 Rong-fen Gong Jie Zhao 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2018年第7期706-716,共11页
Focusing on strip steel surface defects classification, a novel support vector machine with adjustable hyper-sphere (AHSVM) is formulated. Meanwhile, a new multi-class classification method is proposed. Originated f... Focusing on strip steel surface defects classification, a novel support vector machine with adjustable hyper-sphere (AHSVM) is formulated. Meanwhile, a new multi-class classification method is proposed. Originated from support vector data description, AHSVM adopts hyper-sphere to solve classification problem. AHSVM can obey two principles: the margin maximization and inner-class dispersion minimization. Moreover, the hyper-sphere of AHSVM is adjustable, which makes the final classification hyper-sphere optimal for training dataset. On the other hand, AHSVM is combined with binary tree to solve multi-class classification for steel surface defects. A scheme of samples pruning in mapped feature space is provided, which can reduce the number of training samples under the premise of classification accuracy, resulting in the improvements of classification speed. Finally, some testing experiments are done for eight types of strip steel surface defects. Experimental results show that multi-class AHSVM classifier exhibits satisfactory results in classification accuracy and efficiency. 展开更多
关键词 Strip steel surface defect Multi-class classification Supporting vector machine Adjustable hyper-sphere
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Multi-class classification method for steel surface defects with feature noise 被引量:2
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作者 Mao-xiang Chu Yao Feng +1 位作者 Yong-hui Yang Xin Deng 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2021年第3期303-315,共13页
Defect classification is the key task of a steel surface defect detection system.The current defect classification algorithms have not taken the feature noise into consideration.In order to reduce the adverse impact o... Defect classification is the key task of a steel surface defect detection system.The current defect classification algorithms have not taken the feature noise into consideration.In order to reduce the adverse impact of feature noise,an anti-noise multi-class classification method was proposed for steel surface defects.On the one hand,a novel anti-noise support vector hyper-spheres(ASVHs)classifier was formulated.For N types of defects,the ASVHs classifier built N hyper-spheres.These hyper-spheres were insensitive to feature and label noise.On the other hand,in order to reduce the costs of online time and storage space,the defect samples were pruned by support vector data description with parameter iteration adjustment strategy.In the end,the ASVHs classifier was built with sparse defect samples set and auxiliary information.Experimental results show that the novel multi-class classification method has high efficiency and accuracy for corrupted defect samples in steel surface. 展开更多
关键词 Steel surface defect Multi-class classification Anti-noise support vector hyper-sphere Parameter iteration adjustment Feature noise
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AN IMPROVED ADAPTIVE THRESHOLD MODULATION METHOD FOR JITTER REDUCTION IN SDH/SONET
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作者 Shi Fuqiang Lin Xiaokang Feng Chongxi (Communication Div., Electron. Eng. Dept., Tsinghua University, Beijing 100084) 《Journal of Electronics(China)》 1999年第3期251-256,共6页
Adaptive threshold modulation is widely adopted in SDH/SONET network for pointer processing and mapping. When the processing rate is very high, the performance of an all digital implementation is limited by the phase ... Adaptive threshold modulation is widely adopted in SDH/SONET network for pointer processing and mapping. When the processing rate is very high, the performance of an all digital implementation is limited by the phase error resolution. Phase error re-sampling technique is adopted here for the all digital implementation of an improved adaptive threshold modulation, which can work in greatly reduced operating speed with high jitter and wander performance. The improved method is adopted in AU-4 and TU-12 pointer processors and the simulated performance is given. 展开更多
关键词 POINTER adjustment Adaptive threshold MODULATION JITTER WANDER
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Incremental Training for SVM-Based Classification with Keyword Adjusting
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作者 SUNJin-wen YANGJian-wu LUBin XIAOJian-guo 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第5期805-811,共7页
This paper analyzed the theory of incremental learning of SVM (support vector machine) and pointed out it is a shortage that the support vector optimization is only considered in present research of SVM incremental le... This paper analyzed the theory of incremental learning of SVM (support vector machine) and pointed out it is a shortage that the support vector optimization is only considered in present research of SVM incremental learning. According to the significance of keyword in training, a new incremental training method considering keyword adjusting was proposed, which eliminates the difference between incremental learning and batch learning through the keyword adjusting. The experimental results show that the improved method outperforms the method without the keyword adjusting and achieve the same precision as the batch method. Key words SVM (support vector machine) - incremental training - classification - keyword adjusting CLC number TP 18 Foundation item: Supported by the National Information Industry Development Foundation of ChinaBiography: SUN Jin-wen (1972-), male, Post-Doctoral, research direction: artificial intelligence, data mining and system integration. 展开更多
关键词 SVM (support vector machine) incremental training classification keyword adjusting
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基于图像匹配的宽基线牛只面部图像识别研究 被引量:1
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作者 翁智 刘永兴 +1 位作者 刘科 郑志强 《中国农业大学学报》 北大核心 2025年第3期49-59,共11页
为提升识别模型对非标准化数据的适应性,本研究设计了一种基于图像匹配的宽基线牛只面部识别方法,采用SuperPoint与SuperGlue构建图像匹配算法,并针对性改进以提高识别准确率。在特征点提取过程中,引入了基于图像质量评估的动态阈值调... 为提升识别模型对非标准化数据的适应性,本研究设计了一种基于图像匹配的宽基线牛只面部识别方法,采用SuperPoint与SuperGlue构建图像匹配算法,并针对性改进以提高识别准确率。在特征点提取过程中,引入了基于图像质量评估的动态阈值调整策略,对图像的清晰度、边缘密度及纹理特性进行量化评估,并据此调整SuperPoint的阈值,实现高质量特征点提取。同时,通过评估特征点的分布熵与空间覆盖性,调整SuperGlue的匹配阈值,以实现高效匹配。为验证方法有效性,在自建牛只面部数据集上与多种图像匹配方法进行了对比试验。结果表明:1)算法在窄基线数据集上的宏平均精确率、宏平均召回率及宏平均F1分别为92.1%、90.4%和91.2%。2)算法在宽基线数据集上的宏平均精确率、宏平均召回率及宏平均F1分别为82.8%、81.0%和81.9%。3)算法在公开数据集上的微平均F1得分为86.4%。各项结果均显著优于传统图像匹配算法。综上,本研究提出了一种全新的图像匹配算法,有效提升了牛只面部识别模型对非标准化数据的适应性,为牛面部识别方法的实际应用提供技术参考。 展开更多
关键词 牛个体识别 特征匹配 动态阈值调整 面部识别
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