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Comparing the Area of Data Mining Algorithms in Network Intrusion Detection 认领
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作者 Yasamin Alagrash Azhar Drebee Nedda Zirjawi 《信息安全(英文)》 2020年第1期1-18,共18页
The network-based intrusion detection has become common to evaluate machine learning algorithms. Although the KDD Cup’99 Dataset has class imbalance over different intrusion classes, still it plays a significant role... The network-based intrusion detection has become common to evaluate machine learning algorithms. Although the KDD Cup’99 Dataset has class imbalance over different intrusion classes, still it plays a significant role to evaluate machine learning algorithms. In this work, we utilize the singular valued decomposition technique for feature dimension reduction. We further reconstruct the features form reduced features and the selected eigenvectors. The reconstruction loss is used to decide the intrusion class for a given network feature. The intrusion class having the smallest reconstruction loss is accepted as the intrusion class in the network for that sample. The proposed system yield 97.90% accuracy on KDD Cup’99 dataset for the stated task. We have also analyzed the system with individual intrusion categories separately. This analysis suggests having a system with the ensemble of multiple classifiers;therefore we also created a random forest classifier. The random forest classifier performs significantly better than the SVD based system. The random forest classifier achieves 99.99% accuracy for intrusion detection on the same training and testing data set. 展开更多
关键词 Feature Reduction SINGULAR Value Decomposition INTRUSION DETECTION Correlation Analysis Association Impact Scale INTRUSION DETECTION System KDD CUP 1999 Random FOREST
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Data-Driven Approaches for Spatio-Temporal Analysis:A Survey of the State-of-the-Arts 认领
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作者 Monidipa Das Soumya K.Ghosh 《计算机科学技术学报:英文版》 SCIE EI CSCD 2020年第3期665-696,共32页
With the advancement of telecommunications,sensor networks,crowd sourcing,and remote sensing technology in present days,there has been a tremendous growth in the volume of data having both spatial and temporal referen... With the advancement of telecommunications,sensor networks,crowd sourcing,and remote sensing technology in present days,there has been a tremendous growth in the volume of data having both spatial and temporal references.This huge volume of available spatio-temporal(ST)data along with the recent development of machine learning and computational intelligence techniques has incited the current research concerns in developing various data-driven models for extracting useful and interesting patterns,relationships,and knowledge embedded in such large ST datasets.In this survey,we provide a structured and systematic overview of the research on data-driven approaches for spatio-temporal data analysis.The focus is on outlining various state-of-the-art spatio-temporal data mining techniques,and their applications in various domains.We start with a brief overview of spatio-temporal data and various challenges in analyzing such data,and conclude by listing the current trends and future scopes of research in this multi-disciplinary area.Compared with other relevant surveys,this paper provides a comprehensive coverage of the techniques from both computational/methodological and application perspectives.We anticipate that the present survey will help in better understanding various directions in which research has been conducted to explore data-driven modeling for analyzing spatio-temporal data. 展开更多
关键词 data-driven modeling spatio-temporal data PREDICTION change pattern detection outlier detection hotspot detection partitioning/summarization (tele-)coupling visual analytics
Principal-component estimates of the Kuroshio Current axis and path based on the mathematical verification between satellite altimeter and drifting buoy data 认领
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作者 Zhanpeng Zhuang Zhenli Hui +2 位作者 Guangbing Yang Xinhua Zhao Yeli Yuan 《海洋学报:英文版》 SCIE CAS CSCD 2020年第1期14-24,共11页
We used satellite altimetry data to investigate the Kuroshio Current because of the higher resolution and wider range of observations. In previous studies, satellite absolute geostrophic velocities were used to study ... We used satellite altimetry data to investigate the Kuroshio Current because of the higher resolution and wider range of observations. In previous studies, satellite absolute geostrophic velocities were used to study the spatiotemporal variability of the sea surface velocity field along the current, and extraction methods were employed to detect the Kuroshio axes and paths. However, sea surface absolute geostrophic velocity estimated from absolute dynamic topography should be regarded as the geostrophic component of the actual surface velocity, which cannot represent a sea surface current accurately. In this study, mathematical verification between the climatic absolute geostrophic and bin-averaged drifting buoy velocity was established and then adopted to correct the satellite absolute geostrophic velocities. There were some differences in the characteristics between satellite geostrophic and drifting buoy velocities. As a result, the corrected satellite absolute geostrophic velocities were used to detect the Kuroshio axis and path based on a principal-component detection scheme. The results showed that the detection of the Kuroshio axes and paths from corrected absolute geostrophic velocities performed better than those from satellite absolute geostrophic velocities and surface current estimations. The corrected satellite absolute geostrophic velocity may therefore contribute to more precise day-to-day detection of the Kuroshio Current axis and path. 展开更多
关键词 KUROSHIO AXIS DETECTION KUROSHIO PATH DETECTION MATHEMATICAL VERIFICATION satellite absolute geostrophic velocity principal-component DETECTION
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Cyclodextrin derivatives functionalized highly sensitive chiral sensor based on organic field-effect transistor 认领
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作者 Yifan Wu Xuepeng Wang +2 位作者 Xiaoxuan Li Yin Xiao Yong Wang 《中国化学快报:英文版》 SCIE CAS CSCD 2020年第1期99-102,共4页
Novel highly sensitive chiral organic field-effect transistors(COFET)were developed by directly assembling imidazolium3,5-dimethylphenylcabamoylated-β-cyclodextrin(lm^+-Ph-β-CD)and 3,5-dimethylphenylcarbamoylated-β... Novel highly sensitive chiral organic field-effect transistors(COFET)were developed by directly assembling imidazolium3,5-dimethylphenylcabamoylated-β-cyclodextrin(lm^+-Ph-β-CD)and 3,5-dimethylphenylcarbamoylated-β-CD(Ph-β-CD)respectively onto the semiconductor layer as sensing units.The Im+-Ph-β-CD/COFET afforded better enantioselectivity and a lowest detection concentration of10^-18 L/mol as well as the potentiality in quantitative analysis of commercial medicines. 展开更多
关键词 CHIRAL DISCRIMINATION OFET SENSOR Β-CYCLODEXTRIN derivatives Real-time DETECTION Quantitative DETECTION
Express and sensitive detection of multiple miRNAs via DNA cascade reactors functionalized photonic crystal array 认领
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作者 Yingfei Wang Yuyi Li +3 位作者 Yue Zhang Kewei Ren Huangxian Ju Ying Liu 《中国科学:化学英文版》 SCIE EI CAS CSCD 2020年第5期731-740,共10页
Array based detection techniques with fluorescence signal reading is a powerful tool for multiple targets analysis. However,when applied fluorescence array for micro RNA detection, time-consuming multi-steps surface s... Array based detection techniques with fluorescence signal reading is a powerful tool for multiple targets analysis. However,when applied fluorescence array for micro RNA detection, time-consuming multi-steps surface signal amplification is usually required due to the low abundance of micro RNA in total RNA expressions, which impairs detection efficiency and limits its application in point of care test(POCT) manner. Herein, DNA cascade reactors(DCRs) functionalized photonic crystal(PC)array was fabricated for express and sensitive detections of mi RNA-21 and mi RNA-155. DCRs were assembled by interval conjugation of self-quenched hairpin DNA probes to single strand DNA nanowire synthesized by rolling circle amplification,which generated cascade DNA hybridization reactions in response to target mi RNAwith instant fluorescence recovery signal. PC array patterns with multi-structure colors further amplified fluorescence with their respective photonic bandgaps(PBGs)matching with the emission peaks of fluorescence molecules labelled on DCRs. The as-prepared DCRs functionalized PC array demonstrated express and sensitive simultaneous detections of mi RNA-21 and mi RNA-155 with hundreds f M detection limits only in 15 min, and was successfully applied in fast quantifications of low abundance mi RNAs from cell lysates and spiked mi RNAs from human serum, which would hold great potential for disease diagnosis and therapeutic effect monitoring with a POCT manner. 展开更多
关键词 micro RNA detection photonic crystal array DNA cascade reactors fluorescence amplification express detection
Destructive and Nondestructive Determination of <sup>226</sup>Ra and <sup>228</sup>Ra in Drinking Water by Gamma Spectrometry 认领
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作者 A. J. Khan A. Bari +3 位作者 M. A. Torres D. K. Haines T. J. Hoffman T. M. Semkow 《环境保护(英文)》 2020年第4期257-268,共12页
The Safe Drinking Water Act (SDWA) mandates that the drinking water should be monitored for 226Ra and 228Ra isotopes and establishes the Maximum Contaminant Level of 185 mBq/L (5 pCi·L-1) for the sum. In addition... The Safe Drinking Water Act (SDWA) mandates that the drinking water should be monitored for 226Ra and 228Ra isotopes and establishes the Maximum Contaminant Level of 185 mBq/L (5 pCi·L-1) for the sum. In addition, SDWA regulates the Detection Limit (DL) of 37.0 mBq/L (1 pCi/L) for each isotope. The purpose of this work is to develop a working method for the determination of radium isotopes in drinking water satisfying the regulatory requirements of U.S. Environmental Protection Agency by utilizing our extensive experience in low-background gamma spectrometry at this laboratory. Two versions of the method were studied: destructive and non-destructive. Destructive method used the BaSO4 coprecipitation as well as 133Ba tracer for chemical recovery. We have used three gamma spectrometers: low-background 102% and 134% efficient with top muon guards, as well as an ultralow-background 140% efficient with full muon guard. We obtained a range of DLs from 5.3 to 22.6 mBq/L for 226Ra and from 7.4 to 30.4 mBq/L for 228Ra using the destructive method. For non-destructive method, the DL range was 26.0 to 26.9 mBq/L for 226Ra and 27.6 to 28.6 mBq/L for 228Ra using the 140% detector. To verify the methods, 7 to 10 laboratory control samples were spiked with both 226Ra and 228Ra at two different activities of 37.0 and 185 mBq/L. The results were evaluated by performing a combined location/variance chi-square test at a right-tail significance of 0.01 (99% Confidence Level), as stipulated by EPA. The verification results passed the chi-square tests at both activity levels. The destructive method can be accomplished using low-background gamma spectrometry, whereas non-destructive method requires ultralow-background gamma spectrometry. 展开更多
关键词 RADIOACTIVE Pollution GERMANIUM Detector Detection Limit CHI-SQUARE Test
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Rapid detection of Pseudomonas aeruginosa by cross priming amplification 认领
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作者 XIANG Yong YAN Ling +3 位作者 ZHENG Xiao-cui LI Li-zhen LIU Peng CAO Wei-sheng 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第10期2523-2529,共7页
Pseudomonas aeruginosa(PA)is an opportunistic pathogen of humans and animals and a common source of nosocomial infections especially of the respiratory tract.Pseudomonas aeruginosa is also a major bacterial disease of... Pseudomonas aeruginosa(PA)is an opportunistic pathogen of humans and animals and a common source of nosocomial infections especially of the respiratory tract.Pseudomonas aeruginosa is also a major bacterial disease of poultry and in particular,eggs and newly hatched chicks.In this study,we developed a simple,accurate and rapid molecular detection method using cross priming amplification(CPA)with a nucleic acid test strip to detect P.aeruginosa.The assay efficiently amplified the target gene within 45 min at 62℃only using a simple water bath.The detection limit of the method was 1.18x 102 copiesμL^-1 for plasmid DNA and 4.4 CFU mL^-1 for bacteria in pure culture,and was 100 times more sensitive than conventional PCR.We screened 83 clinical samples from yellow-feather broiler breeder chickens and hospitalized/treated dogs and cats using CPA,PCR and traditional culture methods.The positive sample ratios were 15.3%(13/83)by CPA,13.3%(11/83)by PCR and 12.1%(10/83)by the culture method.The established CPA method has significant advantages for detecting P.aeruginosa.The method is easy to use and possesses high specificity and sensitivity without the requirements of complicated experimental equipment.The PA-CPA assay is especially fit for outdoor and primary medical units and is an ideal system for the rapid detection and monitoring of P.aeruginosa. 展开更多
关键词 Pseudomonas aeruginosa cross priming amplification isothermal amplification rapid detection detection method
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海上钻井平台综合信息防护系统 认领
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作者 王根成 黄斌 《现代导航》 2020年第4期305-307,312,共4页
作为石油工业海上作业的重要利器,海上钻井平台面临着恐怖威胁和盗抢的诸多危险。搭建海上钻井平台综合防护系统,是降低风险的必要手段。综合防护系统由指控台、探测分系统、通讯分系统、处置分系统组成,主要设备包括:雷达、声纳、漂浮... 作为石油工业海上作业的重要利器,海上钻井平台面临着恐怖威胁和盗抢的诸多危险。搭建海上钻井平台综合防护系统,是降低风险的必要手段。综合防护系统由指控台、探测分系统、通讯分系统、处置分系统组成,主要设备包括:雷达、声纳、漂浮式海面围栏、光纤探测阻拦网、定向强声驱散器、致眩照明装置等。通过主动探测,发现水面、水下的入侵威胁,利用物理隔离手段和非致命武器驱除入侵破坏和盗抢者,达到保卫海上钻井平台的目的。 展开更多
关键词 钻井平台 指控 探测 通讯 处置 雷达 声纳 漂浮式海面围栏 光纤探测阻拦网 定向强声驱散器 致眩照明装置
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Comparison of Economically Favourable and Further Development Friendly DNA Isolation Methods from Microbial Cultures 认领
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作者 Barbara Bánkuti Zoltán Tudós +7 位作者 Susan Szathmary László Stipkovits Zsófia Sipos-Kozma Balázs ásványi ádám Józsa Július Raj?áni Kálmán Szenthe Ferenc Bánáti 《微生物学(英文)》 2020年第1期1-13,共13页
Microorganisms, regardless of whether pathogenic or not, may cause enormous economic losses due to adverse effects on human and animal health, or by damaging the quality of the agricultural and food products. Based on... Microorganisms, regardless of whether pathogenic or not, may cause enormous economic losses due to adverse effects on human and animal health, or by damaging the quality of the agricultural and food products. Based on these effects, the development of prompt molecular methods and their involvement in the practical pathogen diagnostic diagnostics is more than actual. This paper is focused on the evaluation of easy-to-perform and highly budget-friendly, PCR-related DNA purification protocols for diagnostic purposes especially in water or similar simple matrices. The slight modifications of earlier described DNA isolation methods, which rely on chelate exchange resin and/or ethanol-sodium-based heat lysis, we reevaluated in comparison with a widely used commercial kit. The efficiency of DNA purification techniques was assessed from Gramnegative as well as Gram-positive bacteria and yeast using quantitative PCR. The effectivity of different methods tested may vary depending on the bacterial or yeast species in question. Nevertheless, in our hands, the chelate exchange resin-based methods were found to be the most robust and/or satisfying at least by an acceptable reproducibility rate. Our presented results support the potential of low-cost but still sensitive molecular microbe detection procedures consisting of only a few pipetting steps resulting in good reproducibility and the least possible environmental burden, serving as a good starting point for developments of matrix-specific processes and methods. 展开更多
关键词 MICROBE Detection DNA PURIFICATION LYSIS qPCR DEVELOPMENTAL POTENTIAL
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固相微萃取-气相色谱联用法在水环境重金属离子污染检测中的应用 认领
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作者 宋萍 《世界有色金属》 2020年第5期297-298,共2页
对于水体的重金属离子物污染检测中,常常采取原子吸收光谱法,但是传统的原子吸收光谱法不能进行多元素同时分析,而且该检测方法精度较低。而对于固相微萃取-气相色谱联用法在水环境重金属离子污染检测中的应用研究,在温度控制中放弃传... 对于水体的重金属离子物污染检测中,常常采取原子吸收光谱法,但是传统的原子吸收光谱法不能进行多元素同时分析,而且该检测方法精度较低。而对于固相微萃取-气相色谱联用法在水环境重金属离子污染检测中的应用研究,在温度控制中放弃传统的继电器加热方法,采用电压及PID控制器进行温度控制,设计了采用气相色谱联用法对于水环境重金属离子污染检测的方法,给出了改良后的检测流程,经过实验对比分析,运用气相色谱联用法与传统原子吸收光谱法对比误差率更低。 展开更多
关键词 检测 精度 温度控制 检测流程
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Detection of “Swollen Shoot” Disease in Ivorian Cocoa Trees via Convolutional Neural Networks 认领
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作者 Mamadou Coulibaly Konan Hyacinthe Kouassi +1 位作者 Silue Kolo Olivier Asseu 《工程(英文)(1947-3931)》 2020年第3期166-176,共11页
Recent advances in diagnostics have made image analysis one of the main areas of research and development. Selecting and calculating these characteristics of a disease is a difficult task. Among deep learning techniqu... Recent advances in diagnostics have made image analysis one of the main areas of research and development. Selecting and calculating these characteristics of a disease is a difficult task. Among deep learning techniques, deep convolutional neural networks are actively used for image analysis. This includes areas of application such as segmentation, anomaly detection, disease classification, computer-aided diagnosis. The objective which we aim in this article is to extract information in an effective way for a better diagnosis of the plants attending the disease of “swollen shoot”. 展开更多
关键词 DRONE Convolutional NEURAL Networks Image Recognition FEATURE DETECTION
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FEW-NNN: A Fuzzy Entropy Weighted Natural Nearest Neighbor Method for Flow-Based Network Traffic Attack Detection 认领
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作者 Liangchen Chen Shu Gao +2 位作者 Baoxu Liu Zhigang Lu Zhengwei Jiang 《中国通信:英文版》 SCIE CSCD 2020年第5期151-167,共17页
Attacks such as APT usually hide communication data in massive legitimate network traffic, and mining structurally complex and latent relationships among flow-based network traffic to detect attacks has become the foc... Attacks such as APT usually hide communication data in massive legitimate network traffic, and mining structurally complex and latent relationships among flow-based network traffic to detect attacks has become the focus of many initiatives. Effectively analyzing massive network security data with high dimensions for suspicious flow diagnosis is a huge challenge. In addition, the uneven distribution of network traffic does not fully reflect the differences of class sample features, resulting in the low accuracy of attack detection. To solve these problems, a novel approach called the fuzzy entropy weighted natural nearest neighbor(FEW-NNN) method is proposed to enhance the accuracy and efficiency of flowbased network traffic attack detection. First, the FEW-NNN method uses the Fisher score and deep graph feature learning algorithm to remove unimportant features and reduce the data dimension. Then, according to the proposed natural nearest neighbor searching algorithm(NNN_Searching), the density of data points, each class center and the smallest enclosing sphere radius are determined correspondingly. Finally, a fuzzy entropy weighted KNN classification method based on affinity is proposed, which mainly includes the following three steps: 1、 the feature weights of samples are calculated based on fuzzy entropy values, 2、 the fuzzy memberships of samples are determined based on affinity among samples, and 3、 K-neighbors are selected according to the class-conditional weighted Euclidean distance, the fuzzy membership value of the testing sample is calculated based on the membership of k-neighbors, and then all testing samples are classified according to the fuzzy membership value of the samples belonging to each class;that is, the attack type is determined. The method has been applied to the problem of attack detection and validated based on the famous KDD99 and CICIDS-2017 datasets. From the experimental results shown in this paper, it is observed that the FEW-NNN method improves the accuracy and efficiency of f 展开更多
关键词 fuzzy entropy weighted KNN network attack detection fuzzy membership natural nearest neighbor network security intrusion detection system
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Bridge Girder Crack Assessment Using Faster RCNN Inception V2 and Infrared Thermography 认领
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作者 Murad Al Qurishee Weidong Wu +4 位作者 Babatunde Atolagbe Joseph Owino Ignatius Fomunung Said El Said Sayed Mohammad Tareq 《交通科技期刊(英文)》 2020年第2期110-127,共18页
Manual inspections of infrastructures such as highway bridge, pavement, dam, and multistoried garage ceiling are time consuming, sometimes can be life threatening, and costly. An automated computerized system can redu... Manual inspections of infrastructures such as highway bridge, pavement, dam, and multistoried garage ceiling are time consuming, sometimes can be life threatening, and costly. An automated computerized system can reduce time, faulty inspection, and cost of inspection. In this study, we developed a computer model using deep learning Convolution Neural Network (CNN), which can be used to automatically detect the crack and non-crack type structure. The goal of this research is to allow application of state-of-the-art deep neural network and Unmanned Aerial Vehicle (UAV) technologies for highway bridge girder inspection. As a pilot study of implementing deep learning in Bridge Girder, we study the recognition, length, and location of crack in the structure of the UTC campus old garage concrete ceiling slab. A total of 2086 images of crack and non-crack were taken from UTC Old Library parking garage ceiling using handheld mobile phone and drone. After training the model shows 98% accuracy with crack and non-crack types of structures. 展开更多
关键词 Bridge GIRDER CONVOLUTION Neural Network CRACK Detection Structural Health Monitoring Infrared THERMOGRAPHY
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Asymmetric polymerase chain reaction and loop-mediated isothermal amplification(AP-LAMP) for ultrasensitive detection of microRNAs 认领
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作者 Ruili Wang Ling Lan +1 位作者 Li Liu Liang Cheng 《中国化学快报:英文版》 SCIE CAS CSCD 2020年第1期159-162,共4页
In this manuscript,we first report an ultrasensitive detection assay of microRNA by combing asymmetric polymerase chain reaction(A-PCR)and loop-mediated isothermal amplification(LAMP)technology.Using A-PCR obtained an... In this manuscript,we first report an ultrasensitive detection assay of microRNA by combing asymmetric polymerase chain reaction(A-PCR)and loop-mediated isothermal amplification(LAMP)technology.Using A-PCR obtained an extended single strand to form LAMP stem-loop structure under isothermal amplification conditions.We used miRNAs as a loop primer probe in LAMP reaction and completed its ultrasensitive and rapid detection.The established method furnished a fast,specific and efficient detection of target miRNA with a detection limit as low as 10 amol/L in 90 min. 展开更多
关键词 microRNA LAMP ASYMMETRIC PCR Ultrasensitive DETECTION RAPID DETECTION
Fabrication of oxygen-doped MoSe2 hierarchical nanosheets for highly sensitive and selective detection of trace trimethylamine at room temperature in air 认领
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作者 Nannan Hou Qianqian Sun +8 位作者 Jing Yang Su You Yun Cheng Qian Xu Wei Li Shiqi Xing Li Zhang Junfa Zhu Qing Yang 《纳米研究:英文版》 SCIE EI CAS CSCD 2020年第6期1704-1712,共9页
Nano Research volume 13,pages1704–1712(2020)Cite this article 191 Accesses Metrics details Abstract Intelligent gas sensors based on the layered transition metal dichalcogenides(TMDs)have attracted great interest in ... Nano Research volume 13,pages1704–1712(2020)Cite this article 191 Accesses Metrics details Abstract Intelligent gas sensors based on the layered transition metal dichalcogenides(TMDs)have attracted great interest in the field of gas sensing due to their multiple active sites,fast electron,mass transfer capability and large surface-to-volume ratio.However,conventional TMDs-based sensors typically work at elevated temperature in inert atmosphere,which would largely limit the corresponding practical applications.Herein,novel oxygen-doped MoSe2 hierarchical nanostructures composed of ultrathin nanosheets with large specific surface area have been designed and generated typically at 200°C in air for fast and facile gas sensing of trimethylamine(TMA),effectively.Benefited from the gas-accessible hierarchical morphology and high surface area with abundant nanochannels,highly sensitive and selective detection of trace TMA has been achieved under ambient condition,and as detected the theoretical limit of detection(LOD)is 8 ppb,which is the lowest for TMA detection under ambient condition among the reported studies.The mechanism of oxygen doping on the improved gas-sensing performance has been investigated,revealing that the oxygen doping could greatly optimize the electronic structure,thus regulate the Fermi level of MoSe2 as well as the affinity between TMA molecule and sensor surface.It is expected that the oxygen doping strategy developed for the highly efficient gas sensors based on TMDs in present work may also be applicable to other types of gas-sensing semiconductors,which could open up a new direction for the rational design of high-performance gas sensors working under ambient condition. 展开更多
关键词 oxygen-doped MoSe2 nanosheet ambient gas sensing trimethylamine detection highly selective trace detection limit
MHSS ARAIM Algorithm Combined with Gross Error Detection 认领
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作者 Yabin ZHANG Li WANG +1 位作者 Lihong FAN Xuanyu QU 《测绘学报(英文版)》 2020年第1期36-44,共9页
Due to some shortcomings in the current multiple hypothesis solution separation advanced receiver autonomous integrity monitoring(MHSS ARAIM)algorithm,such as the weaker robustness,a number of computational subsets wi... Due to some shortcomings in the current multiple hypothesis solution separation advanced receiver autonomous integrity monitoring(MHSS ARAIM)algorithm,such as the weaker robustness,a number of computational subsets with the larger computational load,a method combining MHSS ARAIM with gross error detection is proposed in this paper.The gross error detection method is used to identify and eliminate the gross data in the original data first,then the MHSS ARAIM algorithm is used to deal with the data after the gross error detection.Therefore,this makes up for the weakness of the MHSS ARAIM algorithm.With the data processing and analysis from several international GNSS service(IGS)and international GNSS monitoring and assessment system(iGMAS)stations,the results show that this new algorithm is superior to MHSS ARAIM in the localizer performance with vertical guidance down to 200 feet service(LPV-200)when using GPS and BDS measure data.Under the assumption of a single-faulty satellite,the effective monitoring threshold(EMT)is improved about 22.47%and 9.63%,and the vertical protection level(VPL)is improved about 32.28%and 12.98%for GPS and BDS observations,respectively.Moreover,under the assumption of double-faulty satellites,the EMT is improved about 80.85%and 29.88%,and the VPL is improved about 49.66%and 18.24%for GPS and BDS observations,respectively. 展开更多
关键词 GROSS ERROR DETECTION ARAIM FAULT DETECTION and IDENTIFICATION MHSS ARAIM
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Molecular Detection of Sugarcane Ratoon Stunting Disease in Hainan Sugarcane-growing Areas 认领
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作者 Shen Linbo Xiong Guoru +6 位作者 Feng Xiaoyan Wang Wenzhi Feng Cuilian Zhao Tingting Wang Jungang Wu Nannan Zhang Shuzhen 《Plant Diseases and Pests(植物病虫害研究:英文版)》 CAS 2020年第1期6-9,共4页
[Objective]The paper was to clarify the occurrence of sugarcane ratoon stunting disease(RSD)in Hainan sugarcane-growing areas.[Method]In 2019,270 samples of sugarcane leaves were collected from six main sugarcane-grow... [Objective]The paper was to clarify the occurrence of sugarcane ratoon stunting disease(RSD)in Hainan sugarcane-growing areas.[Method]In 2019,270 samples of sugarcane leaves were collected from six main sugarcane-growing areas in Hainan Province,and RSD was detected by PCR assay with specific primers.[Result]RSD was detected out in 41 out of 270 sugarcane samples,with an average detection rate of15.19%.The detection rates of RSD were different in six sugarcane-growing areas;the detection rate of RSD in Danzhou sugarcane-growing area was the highest of 22.00%;the detection rate of RSD in Lingao sugarcane-growing area was the lowest of 9.26%.RSD was detected out in 8 out of10 main sugarcane cultivars,among which Xintaitang 22 suffered the heaviest damage,with the positive detection rate of 45.83%;RSD had not been detected out in Zhongtang 1 and Zhongtang 2,while the positive detection rates of RSD in the remaining seven sugarcane cultivars were10.00%-31.25%.[Conclusion]RSD commonly occurs in Hainan sugarcane-growing areas.The research results provide a basis for scientific prevention and control of RSD and promotion and application of healthy virus-free sugarcane seedlings. 展开更多
关键词 SUGARCANE SUGARCANE RATOON STUNTING disease(RSD) Molecular DETECTION DETECTION rate HAINAN
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Outage Detection for Distribution Networks Using Limited Number of Power Flow Measurements 认领
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作者 Basel Alnajjab Ananth Narayan Samudrala +3 位作者 Chen Chen Rick S.Blum Soummya Kar Emma M.Stewart 《现代电力系统与清洁能源学报(英文)》 SCIE EI CSCD 2020年第2期315-324,共10页
Accurate topology estimation is crucial for effectively operating modern distribution networks.Line outages in a distribution network change the network topology by disconnecting some parts of the network from the mai... Accurate topology estimation is crucial for effectively operating modern distribution networks.Line outages in a distribution network change the network topology by disconnecting some parts of the network from the main grid.In this paper,an outage detection(or topology estimation)algorithm for radial distribution networks is presented.The algorithm utilizes noisy power flow measurements collected from a subset of lines in the network,and statistical information characterizing errors in forecasting load demands.Additionally,a sensor placement scheme is presented.The sensor placement provides critical sensing for the outage detection algorithm so that any number of possible outages in the network can be detected.The performance of the proposed outage detection algorithm using the proposed sensor placement is demonstrated through several numerical results on the IEEE 123-node test feeder. 展开更多
关键词 Outage detection distribution networks maximum likelihood(ML)detection sensor placement
Shape Retrieval Using Fourier Descriptors Applied to Industrial Process 认领
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作者 Julio-Alejandro Romero-González Rosamaría Romero-González +2 位作者 Marcela Herrera-Navarro Diana-Margarita Córdova-Esparza Hugo Jiménez-Hernández 《电脑和通信(英文)》 2020年第3期43-52,共10页
Nowadays, manufacturing processes are carried out at speeds that they themselves demand and subject to rigorous standards to maintain the quality of materials. An important step to define the quality of products in me... Nowadays, manufacturing processes are carried out at speeds that they themselves demand and subject to rigorous standards to maintain the quality of materials. An important step to define the quality of products in metalworking is the casting process, which principal focus is seeking control and monitoring of properties of materials. Nevertheless, it is not easy due to the high temperatures and gas produced in the vessel. Although some researchers have been attempting to solve these problems, it is difficult to carry out due to hard conditions. This article proposes the analysis of the surface of the liquid metal, that is, the slag on the surface, which is considered as connected spaces characterized by the topology of their discrete surface. These spaces are described through Fast Fourier Transform, associating changes of intensities to the frequency domain and obtaining main features of these frequencies, these features are used to define an enveloping shape that represents the liquid metal. Finally, the results obtained are presented, which, according to them shows that it is possible to characterize the slag, and by which it is possible to spatially locate the molten metal liquid in the refractory. Therefore, this research serves as the basis for the development of new algorithms for level detection and measurement, preventing overflows and damage to refractories. 展开更多
关键词 CONVEX HULL Shape RETRIEVAL Features Detection FOURIER TRANSFORM Vision COMPUTING
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基于2.004μm的离轴石英音叉增强型光声光谱测量CO2的研究 认领
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作者 解颖超 王瑞峰 +2 位作者 曹渊 刘锟 高晓明 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2020年第9期2664-2669,共6页
CO2是大气的重要组成成分,也是现代化工业社会过多燃烧煤炭、石油和天然气的产物。一方面大量的人源排放CO2进入大气是引发温室效应最主要因素,另一方面, CO2是窒息性气体,在封闭环境积累过高的CO2会导致窒息等安全问题。因此发展小型... CO2是大气的重要组成成分,也是现代化工业社会过多燃烧煤炭、石油和天然气的产物。一方面大量的人源排放CO2进入大气是引发温室效应最主要因素,另一方面, CO2是窒息性气体,在封闭环境积累过高的CO2会导致窒息等安全问题。因此发展小型化、高灵敏度的CO2检测技术在大气环境探测、封闭环境工作区域安全监测等方面具有重要意义和应用需求。利用近年来快速发展的小型化石英音叉谐振增强光声光谱技术,采用相对简单的离轴结构方案,开展了探测CO2的研究。离轴石英音叉增强型光声光谱技术具有探测模块体积小、灵敏度高、抗干扰、成本低、功耗低,对激光器要求低等优点,在发展低功耗便携式气体传感器方面具有巨大的潜力。近年来,尤其是随着近红外激光器技术的逐渐成熟,为离轴石英音叉增强型光声光谱技术提供质量更好、能量更高的激励光源,使得离轴石英音叉增强型光声光谱检测技术具有更高的探测灵敏度,实现了在低浓度下对气体进行精确的检测。通过HITRAN 2012分子光谱数据库筛选出适合探测的谱线,选择2.004μm近红外分布反馈式半导体激光器作为激励光源,通过波长调制方式来激发CO2光声信号,并采用二次谐波检测技术实现光声信号的探测。实验中通过对进样CO2气体加湿、优化调制振幅等方式提高检测性能,实现了空气CO2的探测。在常压下,通过配气仪配置不同浓度的CO2样品,开展了浓度与信号的响应特性研究,获得了良好的线性响应结果。同时也开展了相同浓度CO2样品在不同压力下的信号测量研究,并用Allan方差对系统性能进行评估。结果表明,当平均时间为1 000 s时,系统的探测极限为4×10^-3μL·L^-1,在压力150 Torr时可获得最佳的测量信号,常压下系统对CO2的最小探测灵敏度为15μL·L^-1,相应的归一化噪声等效吸收系数为7.33×10^-9,在150 Torr 展开更多
关键词 离轴石英音叉增强型光声光谱 二氧化碳 探测 二次谐波检测技术
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