期刊文献+
共找到22,903篇文章
< 1 2 250 >
每页显示 20 50 100
A dual-RPA based lateral flow strip for sensitive,on-site detection of CP4-EPSPS and Cry1Ab/Ac genes in genetically modified crops 被引量:1
1
作者 Jinbin Wang Yu Wang +7 位作者 Xiuwen Hu Yifan Chen Wei Jiang Xiaofeng Liu Juan Liu Lemei Zhu Haijuan Zeng Hua Liu 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期183-190,共8页
Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSP... Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field. 展开更多
关键词 Genetically modifi ed crops on-site detection Lateral fl ow test strips Dual recombinase polymerase amplification (RPA)
下载PDF
Simplified prediction models for acoustic installation effects of train-mounted equipment
2
作者 David Thompson Dong Zhao Giacomo Squicciarini 《Railway Engineering Science》 EI 2024年第2期125-143,共19页
Acoustic models of railway vehicles in standstill and pass-by conditions can be used as part of a virtual certification process for new trains.For each piece of auxiliary equipment,the sound power measured on a test b... Acoustic models of railway vehicles in standstill and pass-by conditions can be used as part of a virtual certification process for new trains.For each piece of auxiliary equipment,the sound power measured on a test bench is combined with meas-ured or predicted transfer functions.It is important,however,to allow for installation effects due to shielding by fairings or the train body.In the current work,fast-running analytical models are developed to determine these installation effects.The model for roof-mounted sources takes account of diffraction at the corner of the train body or fairing,using a barrier model.For equipment mounted under the train,the acoustic propagation from the sides of the source is based on free-field Green’s functions.The bottom surfaces are assumed to radiate initially into a cavity under the train,which is modelled with a simple diffuse field approach.The sound emitted from the gaps at the side of the cavity is then assumed to propagate to the receivers according to free-field Green’s functions.Results show good agreement with a 2.5D boundary element model and with measurements.Modelling uncertainty and parametric uncertainty are evaluated.The largest variability occurs due to the height and impedance of the ground,especially for a low receiver.This leads to standard deviations of up to 4 dB at low frequencies.For the roof-mounted sources,uncertainty over the location of the corner used in the equivalent barrier model can also lead to large standard deviations. 展开更多
关键词 Train noise Auxiliary equipment Acoustic installation effects Virtual certification UNCERTAINTY
下载PDF
Translation Theory and Techniques in Optometry Literature: A Case Study of the “Optoform 80 Installation and Maintenance Manual”
3
作者 JIANG Fangzhou 《Sino-US English Teaching》 2024年第2期94-97,共4页
Translation of specialized documents in optometry presents unique challenges,requiring a deep understanding of the professional context,terminology,and adherence to specific translation styles.This paper delves into t... Translation of specialized documents in optometry presents unique challenges,requiring a deep understanding of the professional context,terminology,and adherence to specific translation styles.This paper delves into the translation theory and techniques employed in the English-to-Chinese translation of the“Optoform 80 Installation and Maintenance Manual”,serving as a case study.Emphasizing Nida’s theory of functional equivalence,the paper explores the complexities of translating professional optometry literature,focusing on key points and common issues in translating installation and maintenance manuals for optometric devices.Special attention is given to the translation of professional terminology,employing methods such as addition,omission,conversion,and repetition.The translation process aims to meet specific requirements,ensuring accuracy and coherence while aligning with Chinese language conventions.The paper also analyzes translation methods and techniques concerning terminology,prepositions,conjunctions,and handling parallel elements based on practical insights from the Optoform 80 Manual. 展开更多
关键词 optometry translation functional equivalence installation and maintenance manual translation
下载PDF
Construction Safety Management of Mechanical and Electrical Installation Projects
4
作者 Honglou Chi 《Journal of Architectural Research and Development》 2024年第2期50-54,共5页
Various industries today rely on the support of electromechanical equipment,expanding its scope of application and leading to an increase in electromechanical installation projects.However,due to the high level of exp... Various industries today rely on the support of electromechanical equipment,expanding its scope of application and leading to an increase in electromechanical installation projects.However,due to the high level of expertise required and the potential risks involved,it is crucial to emphasize safety management during construction.This paper delves into the significance of construction safety management for electromechanical installation projects,identifies common problems encountered during construction,and proposes solutions.This analysis aims to provide relevant personnel with essential guidance and references for managing electromechanical installation projects safely. 展开更多
关键词 Construction safety Mechanical and electrical installation installation engineering Engineering projects Safety management
下载PDF
Construction Technology of Lightning Protection Devices in Building Electrical Installation Engineering
5
作者 Xuhong Du 《Journal of Electronic Research and Application》 2024年第1期22-27,共6页
To better improve the electrical safety of buildings and fulfill the role of lightning protection and grounding,this article combines cases and discusses seven aspects of lightning protection devices’construction tec... To better improve the electrical safety of buildings and fulfill the role of lightning protection and grounding,this article combines cases and discusses seven aspects of lightning protection devices’construction technology.These aspects include the lightning protection classification of buildings,air terminals,down conductors,grounding devices,division of lightning protection zones,and lightning electromagnetic pulse shielding.Through the introduction of this article,readers can gain a comprehensive understanding of the application and value of lightning protection grounding construction technology in building electrical installation projects. 展开更多
关键词 Building electrical installation engineering Lightning protection grounding
下载PDF
Cheesy material on macroscopic on-site evaluation after endoscopic ultrasound-guided fine-needle biopsy:Don't miss the tuberculosis
6
作者 Hanane Delsa Khadija Bellahammou +1 位作者 Hussein Hassan Okasha Fahd Ghalim 《World Journal of Clinical Cases》 SCIE 2023年第10期2181-2188,共8页
Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)is an excellent investigation to diagnose pancreatic lesions and has shown high accuracy for its use in pathologic diagnosis.Recently,macroscopic on-site evaluat... Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)is an excellent investigation to diagnose pancreatic lesions and has shown high accuracy for its use in pathologic diagnosis.Recently,macroscopic on-site evaluation(MOSE)performed by an endoscopist was introduced as an alternative to rapid on-site cytologic evaluation to increase the diagnostic yield of EUS-FNB.The MOSE of the biopsy can estimate the adequacy of the sample directly by the macroscopic evaluation of the core tissue obtained from EUS-FNB.Isolated pancreatic tuberculosis is extremely rare and difficult to diagnose because of its non-specific signs and symptoms.Therefore,this challenging diagnosis is based on endoscopy,imaging,and the bacteriological and histological examination of tissue biopsies.This uncommon presentation of tuberculosis can be revealed as pancreatic mass mimicking cancer.EUS-FNB can be very useful in providing a valuable histopathological diagnosis.A calcified lesion with a cheesy core in MOSE must be suggestive of tuberculosis,leading to the request of the GeneXpert,which can detect Mycobacterium tuberculosis deoxyribonucleic acid and resistance to rifampicin.A decent diagnostic strategy is crucial to prevent unnecessary surgical resection and to supply conservative management with antitubercular therapy. 展开更多
关键词 Pancreatic tuberculosis Endoscopic ultrasound Fine-needle biopsy Macroscopic on-site evaluation Cheesy material GeneXpert
下载PDF
Dynamic Analysis of A Deep-Water Compliant Vertical Access Riser with A Variable Length During Installation
7
作者 LIANG Wei-xing LOU Min +1 位作者 WANG Yu ZHANG Rui 《China Ocean Engineering》 SCIE EI CSCD 2023年第4期568-579,共12页
Compliant vertical access risers(CVAR)have broad application prospects in deep-water oil and gas transportation.However,the mechanical behaviors of the CVAR with a variable length during installation remains unclear.T... Compliant vertical access risers(CVAR)have broad application prospects in deep-water oil and gas transportation.However,the mechanical behaviors of the CVAR with a variable length during installation remains unclear.To address this issue,based on the flexible segment method,a model of CVAR with a variable length during installation is established in this study,which is verified by the comparison with commercial software.Then,the mechanical behaviors of CVAR during installation are investigated.The results reveal that the CVAR configuration is significantly affected by the buoyancy blocks.The streamwise displacement of CVAR increases with the increase of current velocity.When the BOP weight is insuffcient,obvious upbending is observed in the lower region and transition region,leading to local compression.When the platform moves in the opposite direction to the current,the maximum stress is larger than that of the scenario when the platform moves in the same direction as the current. 展开更多
关键词 compliant vertical access riser installation analysis dynamic performance variable length
下载PDF
Studies on Suction-Assisted Installation Behavior of Suction Caissons in Clay Under Various Undrained Shear Strengths
8
作者 LI Da-yong HOU Xin-yu +2 位作者 ZHANG Yu-kun MA Shi-li LI Shan-shan 《China Ocean Engineering》 SCIE EI CSCD 2023年第6期989-999,共11页
Suction caissons are widely used for anchoring floating platform and offshore wind turbines.Penetration of the suction caisson into the desired position under the combination of its self-weight and applied suction res... Suction caissons are widely used for anchoring floating platform and offshore wind turbines.Penetration of the suction caisson into the desired position under the combination of its self-weight and applied suction resulted from pumping out the encased water is integral to practical engineering.Model tests were carried out to investigate the suctionassisted installation of suction caissons in clay under various undrained shear strengths.It was found that there exists a critical penetration depth value.When the penetration depth is smaller than the critical value,the soil plug undrained shear strength is higher than intact clay(i.e.,clay prior to installation).However,when the penetration depth is greater than the critical penetration depth,the undrained shear strength of soil plug is lower than intact clay.The critical value decreases with the increasing consolidation time and undrained shear strength of clay.During suction-assisted installation,cracks occur around suction caissons.The installation way has little effect on the crack formation.The influence range(i.e.,the maximum distance between the crack and the suction caisson edge)was found to increase with the increasing friction coefficient of interface between the suction caisson wall and soil and decreases with the increasing soil undrained shear strength.In addition,the drained condition of the clay during installation is dominated by the caisson aspect ratio,the undrained shear strength and the friction coefficient between the caisson wall and clay.Equations to estimate the penetration resistance and the required suction to install the suction caisson are summarized. 展开更多
关键词 suction caisson suction-assisted installation model tests undrained shear strength of clay soil deformation
下载PDF
使用IBM Installation Factory简化Web Sphere Application Server的安装和部署
9
作者 杜剑侠 《电子技术与软件工程》 2013年第16期231-232,共2页
本文重点介绍了IBMInstal-lation Factory(以下简称IF)的主要功能,讲解如何使用IF生成定制安装包和集成安装包,以及如何使用生成的定制安装包和集成安装包来简化和标准化Web Sphere Application Server的安装和部署。
关键词 1BM instalL ation Facto ry安装(Sc ratch install)定制安装包集成安装包(IIP)初始(CIP)
下载PDF
One-Step-Installation of Offshore Wind Turbine on Large-Scale Bucket-Top-Bearing Bucket Foundation 被引量:17
10
作者 丁红岩 练继建 +1 位作者 李爱东 张浦阳 《Transactions of Tianjin University》 EI CAS 2013年第3期188-194,共7页
In 2010,the first offshore wind turbine with integrated installation was established in Qidong sea area of Jiangsu Province,China,which led to the implementation phase of one-step-installation technique based on the d... In 2010,the first offshore wind turbine with integrated installation was established in Qidong sea area of Jiangsu Province,China,which led to the implementation phase of one-step-installation technique based on the design and construction of large-scale bucket-top-bearing (LSBTB) bucket foundation.The critical technique of LSBTB bucket foundation included self-floating towing,penetration with adjustment of horizontal levelness,removability and one-step-installation.The process of one-step-installation included the prefabrication of LSBTB bucket foundation in onshore construction base,installation and debugging of wind power,overall water transportation of foundation and wind power system,and installation of foundation and offshore wind turbine on the appointed sea area.The cost of one-step-installation technique was about 5 000 Yuan/kW,which was 30%-50% lower than that of the existing technique.The prefabrication of LSBTB bucket foundation took about two months.During the one-step-installation process,the installation and debugging of wind power and overall water transportation need about one to two days in sea area within 35 m depth.After the proposed technique is industrialized,the cost will be further reduced,and the installation capacity is expected to be up to 500 wind turbines per year. 展开更多
关键词 one-step-installation TECHNIQUE large-scale bucket-top-bearing BUCKET foundation self-floating towing penetration TECHNIQUE with adjustment of horizontal levelness removability TECHNIQUE construction and installation cost
下载PDF
Valuation of the flexibility in decision-making for revamping installations―A case from fertilizer plants 被引量:4
11
作者 WANG Zhen LI Liangjun 《Petroleum Science》 SCIE CAS CSCD 2010年第3期428-434,共7页
This paper puts forward a valuation model for the flexibility of revamping urea plants based on the substitutability of switching between the internationally accepted fertilizer feedstock fuel oil and natural gas. The... This paper puts forward a valuation model for the flexibility of revamping urea plants based on the substitutability of switching between the internationally accepted fertilizer feedstock fuel oil and natural gas. The paper first builds a stochastic mean-reversion model for fuel oil prices and natural gas prices respectively, then estimates and tests the parameters using the fuel oil and natural gas prices data from the U.S. market. This paper also conducts a sensitivity analysis with important parameters. The results show that the real option method can be applied successfully to evaluate the flexibility in decision- making for revamping installations in fertilizer plants or other similar plants. 展开更多
关键词 Real option fertilizer installations fuel oil natural gas mean reversion
下载PDF
An Installation System of Deepwater Risers by An S-Lay Vessel 被引量:4
12
作者 段梦兰 王懿 +3 位作者 Segen ESTEFEN 何宁 李丽娜 陈邦敏 《China Ocean Engineering》 SCIE EI 2011年第1期139-148,共10页
Along with the consumption increase of the petroleum products, more countries have transferred their attentions to the offshore fields, especially the deepwater oil and gas reserves. For deepwater exploitation, the ri... Along with the consumption increase of the petroleum products, more countries have transferred their attentions to the offshore fields, especially the deepwater oil and gas reserves. For deepwater exploitation, the risers must be installed to act as the conduits connecting surface platforms to subsea facilities. In this paper, the typical risers sorted by different classes are introduced, and the correspondent installation methods are presented. By investigating the recent projects performed in the deepwater hot spots, and combining the challenges of HYSY20 l for riser installation, a lifting device developed for assisting riser installation is proposed and detailed to satisfy the installation of deepwater risers in the LW3-1 Gas Field of 1500 m in the South China Sea. Tests on both the functions and performances of such a new system exhibit the satisfaction of meeting all challenging requirements of HYSY201 for application to riser installation in waters up to a depth of 3000 m in the South China Sea. 展开更多
关键词 deepwater riser riser installation lifting device LW3-1 Gas Field South China Sea
下载PDF
Analysis on Interface Shear Stress of Thermally InsulatedOcean Pipelines Under Installation 被引量:2
13
作者 闫澍旺 田英辉 +2 位作者 刘润 王章岭 王金英 《China Ocean Engineering》 SCIE EI 2006年第2期315-323,共9页
It has been proved that the thermally insulated ocean pipeline has advantages over the conventional pipe-in-pipe pipeline. The risk of using the thermally insulated pipeline is that the exterior layers covering the st... It has been proved that the thermally insulated ocean pipeline has advantages over the conventional pipe-in-pipe pipeline. The risk of using the thermally insulated pipeline is that the exterior layers covering the steel pipe may be. pulled off if the shear stress on the interface induced by the pullout fore from the tensioner is greater than the binding fore between two neighboring layers during installation. This paper develops a procedure to calculate the shear stress on the interface. The binding force between two neighboring layers can be determined with full scale model tests. The safety of the thermally insulated pipe under installation can then be checked by comparison of the interface shear stress with the binding force. 展开更多
关键词 thermally insulated pipelines shear stress installation binding force
下载PDF
Numerical Simulation of Float-Over Installation for Offshore Platform 被引量:1
14
作者 Yuesheng Ma Lihao Yuan +1 位作者 Yingfei Zan Fuxiang Huang 《Journal of Marine Science and Application》 CSCD 2018年第1期79-86,共8页
In this paper,a numerical investigation of a float-over installation for an offshore platform is presented to verify the feasibility of the actual installation.The hydrodynamic performance of a T-barge is investigated... In this paper,a numerical investigation of a float-over installation for an offshore platform is presented to verify the feasibility of the actual installation.The hydrodynamic performance of a T-barge is investigated in the frequency domain,and the coupled motions are analyzed in the time domain.We then compare with those of the model test and determine that the response amplitude operator and the time series agree quite well.The barge exhibits favorable hydrodynamic behavior in the considered sea state,and the equipment loads are allowable.Themooring systemand sway fender forces are within the permissible range.Based on these results,we can verify that the actual installation of the offshore platform is feasible.We accurately simulated many important factors and effectively reduced the risk associated with the offshore installation,which is of great importance.As such,we demonstrate that the numerical simulation of the float-over installation for offshore platforms has practical engineering significance. 展开更多
关键词 Float-over installation Offshore platform T-barge Model test MOORING system FENDER collision force Numerical simulation
下载PDF
Improved edge lightweight YOLOv4 and its application in on-site power system work 被引量:5
15
作者 Kexin Li Liang Qin +3 位作者 Qiang Li Feng Zhao Zhongping Xu Kaipei Liu 《Global Energy Interconnection》 EI CAS CSCD 2022年第2期168-180,共13页
A“cloud-edge-end”collaborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge computing equipment utilizes lightweight intelligent recognition algorithm... A“cloud-edge-end”collaborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge computing equipment utilizes lightweight intelligent recognition algorithms for on-site risk assessment and alert.Owing to its lightweight and fast speed,YOLOv4-Tiny is often deployed on edge computing equipment for real-time video stream detection;however,its accuracy is relatively low.This study proposes an improved YOLOv4-Tiny algorithm based on attention mechanism and optimized training methods,achieving higher accuracy without compromising the speed.Specifically,a convolution block attention module branch is added to the backbone network to enhance the feature extraction capability and an efficient channel attention mechanism is added in the neck network to improve feature utilization.Moreover,three optimized training methods:transfer learning,mosaic data augmentation,and label smoothing are used to improve the training effect of this improved algorithm.Finally,an edge computing equipment experimental platform equipped with an NVIDIA Jetson Xavier NX chip is established and the newly developed algorithm is tested on it.According to the results,the speed of the improved YOLOv4-Tiny algorithm in detecting on-site dress code compliance datasets is 17.25 FPS,and the mean average precision(mAP)is increased from 70.89%to 85.03%. 展开更多
关键词 on-site power system work YOLOv4-Tiny Convolution block attention mechanism Efficient channel attention Optimized training methods.
下载PDF
Electric-Arc Plasma Installation for Preparing Nanodispersed Carbon Structures 被引量:1
16
作者 P.STEFANOV D.GARLANOV G.VISSOKOV 《Plasma Science and Technology》 SCIE EI CAS CSCD 2008年第4期484-490,共7页
An electric-arc plasma installation operated in the hidden anode arrangement is constructed and used for the preparation of carbon nanostructures. A contracted plasma arc generated by a plasma torch using an inert gas... An electric-arc plasma installation operated in the hidden anode arrangement is constructed and used for the preparation of carbon nanostructures. A contracted plasma arc generated by a plasma torch using an inert gas is used as heat source. The average mass temperature of arc is higher than 10^4 K, while its power density, which is directly transferred onto the electrode (anode), is - 2 kW/mm^2. The anode contact area formed on the electrode moves against the arc by way of shifting the electrode and is hidden completely in the interior of plasma gas stream moving towards it. As a result of both the direct plasma attack and the opposite movement of streams in the hidden anode contact area, a temperature higher than 6000 K is reached. Thus, intensive vaporization takes place, which forms a saturated plasma-gas-aerosol phase of the initial material of electrode (anode). This gas phase is mixed in and carried by the plasma stream. Over that mixed plasma stream, a controlled process of quenching (fixation) is carried out by twisted turbulent fluid streams. After the fixation, the resultant carbon nano-structures are caught by a filter and collected in a bunker. 展开更多
关键词 electric-arc plasma installation nanodispersed carbon structures
下载PDF
Longitudinal Vibration Analysis of Marine Riser During Installation and Hangoff in Ultra Deepwater 被引量:1
17
作者 Yanbin Wang Deli Gao Jun Fang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2016年第4期357-373,共17页
This paper is concerned with the problem of longitudinal vibration of a 3,000 m long disconnected drilling riser during installation and hangoff operation.The natural frequency,amplitude of vibration displacement and ... This paper is concerned with the problem of longitudinal vibration of a 3,000 m long disconnected drilling riser during installation and hangoff operation.The natural frequency,amplitude of vibration displacement and vibration force of longitudinal vibration have been determined with consideration of the damping effect of the sea water.Results show the natural frequency of riser under these two situations are both decrease with the increase of water depth.The natural frequency of riser in installation operation is bigger than that in hangoff operation.The vibration displacement in hangoff configuration is bigger than that in installation while the vibration force in hangoff configuration is smaller than that in installation configuration.Under the condition of resonance,the vibration displacement increase along riser from top end to the bottom end while the vibration force increase along riser from riser bottom end to the top end. 展开更多
关键词 MARINE RISER installation Hangoff Longitudinal VIBRATION
下载PDF
Dynamic Analysis of A Subsea Suspended Manifold Going Through Splash Zone During Installation 被引量:1
18
作者 WANG Ying-ying YANG Chao +3 位作者 YANG Zhong-shan ZHAO Xiao-yu YIN Jian-xi HU Yang-dong 《China Ocean Engineering》 SCIE EI CSCD 2022年第4期553-564,共12页
The subsea suspended manifold designed to replace the traditional foundation structure with the buoys is a new generation subsea production system that can be suspended at a certain height from the seafloor and rapidl... The subsea suspended manifold designed to replace the traditional foundation structure with the buoys is a new generation subsea production system that can be suspended at a certain height from the seafloor and rapidly recycled by its own buoyancy.Due to complex environmental conditions,its hydrodynamic performance in the splash zone is extremely important for the safety of the whole installation process.In this paper,the mathematical model for the dynamic analysis of the seawater ingress process of the single-layer pre-set horizontal cabin is proposed based on the different center of gravity positions of the buoy.Meanwhile,the theoretical analysis of fiber cable is divided into infinite differential units by the discretization method,and the formulae of the horizontal displacement of the subsea suspended manifold are presented.In addition,the simulations are carried out to verify the rules of the dynamic responses on the subsea suspended manifold system with the consideration of the environmental conditions in the South China Sea.Comparing with the calculated value of the mathematical model of the cabin water ingress,the error of the simulation result by use of FLUENT is about 5.47%.Furthermore,the wave height is greater than the current impact on the lowering manifold system and the azimuth angle of the installation vessel is aligned with the direction of the environmental load. 展开更多
关键词 subsea suspended manifold lowering installation seawater ingress splash zone dynamic response
下载PDF
Random Forests Algorithm Based Duplicate Detection in On-Site Programming Big Data Environment 被引量:1
19
作者 Qianqian Li Meng Li +1 位作者 Lei Guo Zhen Zhang 《Journal of Information Hiding and Privacy Protection》 2020年第4期199-205,共7页
On-site programming big data refers to the massive data generated in the process of software development with the characteristics of real-time,complexity and high-difficulty for processing.Therefore,data cleaning is e... On-site programming big data refers to the massive data generated in the process of software development with the characteristics of real-time,complexity and high-difficulty for processing.Therefore,data cleaning is essential for on-site programming big data.Duplicate data detection is an important step in data cleaning,which can save storage resources and enhance data consistency.Due to the insufficiency in traditional Sorted Neighborhood Method(SNM)and the difficulty of high-dimensional data detection,an optimized algorithm based on random forests with the dynamic and adaptive window size is proposed.The efficiency of the algorithm can be elevated by improving the method of the key-selection,reducing dimension of data set and using an adaptive variable size sliding window.Experimental results show that the improved SNM algorithm exhibits better performance and achieve higher accuracy. 展开更多
关键词 on-site programming big data duplicate record detection random forests adaptive sliding window
下载PDF
A retrievable sensor installation technique for acquiring high frequency signals
20
作者 M. Ge H. R. Hardy Jr H. Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2012年第2期127-139,共13页
The use of in-seam waves for void detection in mines requires the capability of capturing high frequency signals over large distances. For instance, the Airy phase of Love waves which are used for void detection in co... The use of in-seam waves for void detection in mines requires the capability of capturing high frequency signals over large distances. For instance, the Airy phase of Love waves which are used for void detection in coal mines ranges from several hundred to over one thousand Hertz and the expected travel distance of these signals is at least 90 m (equivalent to a detection distance of 45 m) for the technique to be considered practical. In order to obtain high quality and broadband signals, sensors are conventionally grouted at the bottom of boreholes so that the attenuation due to the fractured surface is minimized and the coupling effect is improved. However, to be economically feasible, the expensive and high sensitive sensors must be retrievable so that they can be used repeatedly at the same or other locations. Because of these concerns, a retrievable sensor installation technique was developed. This paper provides a detailed review of the technique as well as a brief discussion of its applications. The technique is simple and reliable for both installation and retrieval operations and can be used for boreholes oriented in any directions. The technique has been demonstrated in over 200 sensor installation/retrieval operations under various borebole conditions, including bituminous coal, anthracite coal, shale, sandstone and trona. With this technique, we were able to detect the high frequency signals required for our projects. For instance, the signals used at a trona mine for void detection have a typical frequency of 5 kHz with the travel distance of 150-200 m. The results of these operations have shown that sensors installed in the prescribed manner exhibit predictable, consistent, and repeatable performance. The technique also provides an economical and reliable means for many other field seismic monitoring applications where high quality and broadband signals are essential, such as microseismic monitoring and geotomography studies. 展开更多
关键词 sensor installation void detection in-seam seismic microseismic geotomography
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部