期刊文献+
共找到2,963篇文章
< 1 2 149 >
每页显示 20 50 100
Power Line Monitoring Data Transmission Using Wireless Sensor Network 被引量:4
1
作者 Lifen Li Huaiyu Zhao 《Journal of Power and Energy Engineering》 2015年第8期83-88,共6页
The WSN used in power line monitoring is long chain structure, and the bottleneck near the Sink node is more obvious. In view of this, A Sink nodes’ cooperation mechanism is presented. The Sink nodes from different W... The WSN used in power line monitoring is long chain structure, and the bottleneck near the Sink node is more obvious. In view of this, A Sink nodes’ cooperation mechanism is presented. The Sink nodes from different WSNs are adjacently deployed. Adopting multimode and spatial multiplexing network technology, the network is constructed into multi-mode-level to achieve different levels of data streaming. The network loads are shunted and the network resources are rationally utilized. Through the multi-sink nodes cooperation, the bottlenecks at the Sink node and its near several jump nodes are solved and process the competition of communication between nodes by channel adjustment. Finally, the paper analyzed the method and provided simulation experiment results. Simulation results show that the method can solve the funnel effect of the sink node, and get a good QoS. 展开更多
关键词 WIRELESS Sensor NETWORK (WSN) Power line Monitoring data TRANSMISSION MULTIMODE NETWORK
下载PDF
Assimilating Surface Observations in a Four-Dimensional Variational Doppler Radar Data Assimilation System to Improve the Analysis and Forecast of a Squall Line Case 被引量:7
2
作者 Xingchao CHEN Kun ZHAO +2 位作者 Juanzhen SUN Bowen ZHOU Wen-Chau LEE 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第10期1106-1119,共14页
This paper examines how assimilating surface observations can improve the analysis and forecast ability of a four- dimensional Variational Doppler Radar Analysis System (VDRAS). Observed surface temperature and wind... This paper examines how assimilating surface observations can improve the analysis and forecast ability of a four- dimensional Variational Doppler Radar Analysis System (VDRAS). Observed surface temperature and winds are assimilated together with radar radial velocity and reflectivity into a convection-permitting model using the VDRAS four-dimensional variational (4DVAR) data assimilation system. A squall-line case observed during a field campaign is selected to investigate the performance of the technique. A single observation experiment shows that assimilating surface observations can influence the analyzed fields in both the horizontal and vertical directions. The surface-based cold pool, divergence and gust front of the squall line are all strengthened through the assimilation of the single surface observation. Three experiments--assimilating radar data only, assimilating radar data with surface data blended in a mesoscale background, and assimilating both radar and surface observations with a 4DVAR cost function--are conducted to examine the impact of the surface data assimilation. Independent surface and wind profiler observations are used for verification. The result shows that the analysis and forecast are improved when surface observations are assimilated in addition to radar observations. It is also shown that the additional surface data can help improve the analysis and forecast at low levels. Surface and low-level features of the squall line-- including the surface warm inflow, cold pool, gust front, and low-level wind--are much closer to the observations after assimilating the surface data in VDRAS. 展开更多
关键词 VDRAS 4-D data assimilation radar data surface data squall line
下载PDF
Evaluation of Two Momentum Control Variable Schemes and Their Impact on the Variational Assimilation of Radar Wind Data:Case Study of a Squall Line 被引量:10
3
作者 Xin LI Mingjian ZENG +3 位作者 Yuan WANG Wenlan WANG Haiying WU Haixia MEI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第10期1143-1157,共15页
Different choices of control variables in variational assimilation can bring about different influences on the analyzed atmospheric state. Based on the WRF model's three-dimensional variational assimilation system, t... Different choices of control variables in variational assimilation can bring about different influences on the analyzed atmospheric state. Based on the WRF model's three-dimensional variational assimilation system, this study compares the be- havior of two momentum control variable options-streamfunction velocity potential (ψ-χ) and horizontal wind components (U-V)-in radar wind data assimilation for a squall line case that occurred in Jiangsu Province on 24 August 2014. The wind increment from the single observation test shows that the ψ-χ control variable scheme produces negative increments in the neighborhood around the observation point because streamfunction and velocity potential preserve integrals of velocity. On the contrary, the U-V control variable scheme objectively reflects the information of the observation itself. Furthermore, radial velocity data from 17 Doppler radars in eastern China are assimilated. As compared to the impact of conventional observation, the assimilation of radar radial velocity based on the U-V control variable scheme significantly improves the mesoscale dynamic field in the initial condition. The enhanced low-level jet stream, water vapor convergence and low-level wind shear result in better squall line forecasting. However, the ψ-χ control variable scheme generates a discontinuous wind field and unrealistic convergence/divergence in the analyzed field, which lead to a degraded precipitation forecast. 展开更多
关键词 three-dimensional variational assimilation momentum control variable Doppler radar data squall line
下载PDF
Ethics Lines and Machine Learning: A Design and Simulation of an Association Rules Algorithm for Exploiting the Data
4
作者 Patrici Calvo Rebeca Egea-Moreno 《Journal of Computer and Communications》 2021年第12期17-37,共21页
Data mining techniques offer great opportunities for developing ethics lines whose main aim is to ensure improvements and compliance with the values, conduct and commitments making up the code of ethics. The aim of th... Data mining techniques offer great opportunities for developing ethics lines whose main aim is to ensure improvements and compliance with the values, conduct and commitments making up the code of ethics. The aim of this study is to suggest a process for exploiting the data generated by the data generated and collected from an ethics line by extracting rules of association and applying the Apriori algorithm. This makes it possible to identify anomalies and behaviour patterns requiring action to review, correct, promote or expand them, as appropriate. 展开更多
关键词 data Mining Ethics lines Association Rules Apriori Algorithm COMPANY
下载PDF
One-End Data Method for Fault Position Estimate of Two-Parallel Transmission Lines
5
作者 张庆超 刘飞 +1 位作者 武永峰 宋文南 《Journal of Beijing Institute of Technology》 EI CAS 2003年第1期105-108,共4页
An accurate numerical algorithm for three-line fault involving different phases from each of two-parallel lines is presented. It is based on one-terminal voltage and current data. The loop and nodel equations comparin... An accurate numerical algorithm for three-line fault involving different phases from each of two-parallel lines is presented. It is based on one-terminal voltage and current data. The loop and nodel equations comparing faulted phase to non-faulted phase of two-parallel lines are introduced in the fault location estimation modal, in which the faulted impedance of remote end is not involved. The effect of load flow and fault resistance on the accuracy of fault location are effectively eliminated, therefore an accurate algorithm of locating fault is derived. The algorithm is demonstrated by digital computer simulations and the results show that errors in locating fault are less than 1%. 展开更多
关键词 power system two-parallel lines fault location estimation one-terminal data
下载PDF
Data Logging and Control of a Remote Inverter Using LoRa and Power Line Communication
6
作者 K. A. Terashmila Lasagani Tariq Iqbal George K. Mann 《Energy and Power Engineering》 2018年第8期351-365,共15页
For decades, the power system was highly centralized. With the growing integration of distributed generations into the system, there is a necessity for bi-directional communication methods to monitor and control the r... For decades, the power system was highly centralized. With the growing integration of distributed generations into the system, there is a necessity for bi-directional communication methods to monitor and control the remote assets. The primary objective of this paper is to develop a communication link for monitoring and controlling a grid-connected inverter in a remote location. Furthermore, the paper presents developments that have been incorporated to improve the communication link. The literature survey indicates that LoRa is superior compared to other technologies, but has some security and reliability issues. This paper also presents an encryption algorithm to improve the security of the LoRa link. Local data storage added to the system before transmitting data increases the system reliability. A display at the transmission end is added to improve the user-friendliness of the communication link. A Powerline Communication link is parallelly added to the LoRa link to improve the reliability. Finally, tests are conducted with an actual inverter and the results are presented. The tests show that the developed communication link has improved security and reliability, while its open nature makes it highly scalable and adaptable for employment in other smart grid applications. 展开更多
关键词 LoRa Application Supervisory CONTROL and data ACQUISITION System INVERTER REMOTE CONTROL Power line COMMUNICATION
下载PDF
抢先赢得商机的Data Mining──基于数据仓库的数据挖掘技术 被引量:2
7
作者 王春梅 王曙燕 《现代电子技术》 2006年第12期98-100,共3页
首先介绍了数据仓库以及在此技术上产生的数据挖掘技术,其次阐述了实现数据挖掘应用的几种工具以及选用工具时应遵循的原则,最后说明了数据挖掘技术现存的问题及他现在重要的商业地位。
关键词 数据仓库(DW) 数据挖掘 联机分析处理(OLAP) 建模
下载PDF
船舶型线生成光顺系统SLINE与计算流体力学软件FLUENT的数据接口实现
8
作者 蔡荣泉 严家文 +1 位作者 王金宝 冯学梅 《船舶》 北大核心 2004年第6期43-46,共4页
实现船舶 CAD专用软件与计算流体力学 (CFD)软件的接口 ,有利于化解整个流动计算工作的瓶颈 ,形成 CFD面向船舶设计的快速响应能力 ,因而具有重要实际意义。本文介绍了本所自主开发的船舶型线生成光顺系统 SL INE与计算流体力学软件 FL
关键词 光顺 数据接口 专用软件 系统 CAD 瓶颈 生成 船舶型线 船舶设计 FLUENT
下载PDF
Machining Line Planner输出STEP-NC数控程序的研究 被引量:1
9
作者 樊留群 刘玉平 《制造技术与机床》 CSCD 北大核心 2010年第7期88-91,共4页
介绍了STEP-NC的概念、数据模型及其结构特点,然后通过对比MLP(Machining Line Planner)和STEP-NC数控程序对特征和操作的不同定义方法,分析了在MLP中特征及加工工艺与STEP-NC的对应关系,探讨了在MLP中实现输出STEP-NC格式的零件加工程... 介绍了STEP-NC的概念、数据模型及其结构特点,然后通过对比MLP(Machining Line Planner)和STEP-NC数控程序对特征和操作的不同定义方法,分析了在MLP中特征及加工工艺与STEP-NC的对应关系,探讨了在MLP中实现输出STEP-NC格式的零件加工程序的方法。 展开更多
关键词 STEP-NC数据模型 数控程序 MACHINING line PLANNER
下载PDF
Three-axis magnetic flux leakage in-line inspection simulation based on finite-element analysis 被引量:4
10
作者 冯健 张峻峰 +2 位作者 卢森骧 王宏阳 马瑞泽 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第1期531-536,共6页
With the increase of pipelines, corrosion leakage accidents happen frequently. Therefore, nondestructive testing technology is important for ensuring the safe operation of the pipelines and energy mining. In this pape... With the increase of pipelines, corrosion leakage accidents happen frequently. Therefore, nondestructive testing technology is important for ensuring the safe operation of the pipelines and energy mining. In this paper, the structure and principle of magnetic flux leakage (MFL) in-line inspection system is introduced first. Besides, a mathematic model of the system according to the ampere circuit rule, flux continuity theorem, and column coordinate transform is built, and the magnetic flux density in every point of space is calculated based on the theory of finite element analysis. Then we analyze and design the disposition of measurement section probes and sensors combining both three-axis MFL in-line inspection and multi-sensor fusion technology. Its advantage is that the three-axis changes of magnetic flux leakage field are measured by the multi-probes at the same time, so we can determine various defects accurately. Finally, the theory of finite element analysis is used to build a finite element simulation model, and the relationship between defects and MFL inspection signals is studied. Simulation and experiment results verify that the method not only enhances the detection ability to different types of defects but also improves the precision and reliability of the inspection system. 展开更多
关键词 magnetic flux leakage in-line inspection multi-sensor data fusion sensor disposition finite element analysis
下载PDF
基于Skyline的输电线路巡检数据可视化系统研究 被引量:2
11
作者 孟秀军 谷连军 《信息与电脑》 2020年第6期141-144,共4页
随着电力建设的迅速发展,输电线路巡检工作逐步采用无人机开展实施,提高了巡检效率,产生了大量非结构化数据,导致不能快速实现多源海量数据的融合、可视化展示。针对传统电力GIS系统无法对非结构化数据融合、展示不足的问题,笔者提出了... 随着电力建设的迅速发展,输电线路巡检工作逐步采用无人机开展实施,提高了巡检效率,产生了大量非结构化数据,导致不能快速实现多源海量数据的融合、可视化展示。针对传统电力GIS系统无法对非结构化数据融合、展示不足的问题,笔者提出了一种基于Skyline的输电线路巡检数据三维可视化方法。最后,通过原型系统的实现验证了系统设计既能初步解决非结构化机巡数据统一化管理的问题,又能提供三维可视化环境,消除了非结构化数据可视化的短板,在实际工作中具有重要的意义。 展开更多
关键词 SKYline 输电线路 巡检数据 三维可视化
下载PDF
On-line monitoring of insulation quality of high voltage electric power equipment
12
作者 SUN He-yi, ZHAO Xue-zeng, NIE Peng, BAI Jing-feng, YANG Yan-zhu (Harbin Institute of Technology, Harbin 150001, China) 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2000年第S1期77-80,共4页
Discusses on-line monitoring of electric parameters, such as dielectric loss, divulging current, equivalent capacitance and running voltage, and presents an on-line monitoring system of insulation quality, based on mo... Discusses on-line monitoring of electric parameters, such as dielectric loss, divulging current, equivalent capacitance and running voltage, and presents an on-line monitoring system of insulation quality, based on monitoring divulging current and dielectric loss of high voltage equipment, and its advantages, such as helping people to discover the hidden problems in a timely manner, to reduce power cut and overhaul and to improve security of power supply. 展开更多
关键词 INSULATION CAPABILITY HIGH-VOLTAGE EQUIPMENT ON-line monitoring data PROCESSING
下载PDF
DATA DRIVEN控制方式图象理解系统的结构性能及改进
13
作者 李力 《北方工业大学学报》 1989年第3期78-82,共5页
本文是以图象理解系统实例分析入手,较详尽地论述了采用DATADRIVEN控制方式的线画解释图象理解系统的硬软件结构,并在评估了系统的可靠性基础上,提出了采用数据驱动和模型驱动双向控制的新观点.
关键词 图象理解 双向控制 结画解释
下载PDF
Approach to monitoring, data processing and regularity on landslip in open-pits
14
作者 MA Zhen-li, LI Zheng-zhong, XU Xin-jun (Liaoning Technical University, Fuxin 123000, China) 《中国有色金属学会会刊:英文版》 CSCD 2005年第S1期132-135,共4页
A new method of landslip monitoring in open-pit is presented, in which the monitoring data processing and a variety of deformation curvilinear drawings are carried out by microcomputer system, based on the practice in... A new method of landslip monitoring in open-pit is presented, in which the monitoring data processing and a variety of deformation curvilinear drawings are carried out by microcomputer system, based on the practice in Haizhou Open-Mine for many years. Meanwhile, the general regularity on landslip in open-pit is acquired. 展开更多
关键词 open-pit landslip OBSERVATION line MONITORING data PROCESSING landslip PREDICTION
下载PDF
GPU Accelerated Marine Data Visualization Method 被引量:1
15
作者 LI Bo CHEN Ge +2 位作者 TIAN Fenglin SHAO Baomin JI Pengbo 《Journal of Ocean University of China》 SCIE CAS 2014年第6期964-970,共7页
The study of marine data visualization is of great value. Marine data, due to its large scale, random variation and multiresolution in nature, are hard to be visualized and analyzed. Nowadays, constructing an ocean mo... The study of marine data visualization is of great value. Marine data, due to its large scale, random variation and multiresolution in nature, are hard to be visualized and analyzed. Nowadays, constructing an ocean model and visualizing model results have become some of the most important research topics of ‘Digital Ocean'. In this paper, a spherical ray casting method is developed to improve the traditional ray-casting algorithm and to make efficient use of GPUs. Aiming at the ocean current data, a 3D view-dependent line integral convolution method is used, in which the spatial frequency is adapted according to the distance from a camera. The study is based on a 3D virtual reality and visualization engine, namely the VV-Ocean. Some interactive operations are also provided to highlight the interesting structures and the characteristics of volumetric data. Finally, the marine data gathered in the East China Sea are displayed and analyzed. The results show that the method meets the requirements of real-time and interactive rendering. 展开更多
关键词 marine data visualization techniques and methodologies spherical ray casting line integral convolution multiquadric method VV-Ocean
下载PDF
A Stable and Efficient Method for Drawing Section Linecs
16
作者 王永洁 徐世新 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1995年第1期84-89,共6页
AStableandEfficientMethodforDrawingSectionLinecs¥(王永洁)(徐世新)WANGYongjieXUShixin(Dept.ofMechanicalEngineering,... AStableandEfficientMethodforDrawingSectionLinecs¥(王永洁)(徐世新)WANGYongjieXUShixin(Dept.ofMechanicalEngineering,HarbinInstituteof... 展开更多
关键词 ss: SECTION line edge-vertex classification data structure
下载PDF
基于离散数据流分割算法的预测方法
17
作者 孙丽君 李方方 胡祥培 《管理科学学报》 CSSCI CSCD 北大核心 2024年第9期48-61,共14页
离散数据流具有不确定性高、演变趋势多变以及多极值性等特征.针对这些特征带来的预测难以兼顾准确性和实时性的问题,提出了基于离散数据流分割算法的预测方法.该方法融合了短期趋势提取与分割点在线自适应检测:预测前基于非参数回归短... 离散数据流具有不确定性高、演变趋势多变以及多极值性等特征.针对这些特征带来的预测难以兼顾准确性和实时性的问题,提出了基于离散数据流分割算法的预测方法.该方法融合了短期趋势提取与分割点在线自适应检测:预测前基于非参数回归短期预测模型和改进的趋势提取算法获取短期(预测日)趋势,提前挖掘、分析预测日的短期趋势规律,以用于在线预测;预测时主要针对在线的数据流,基于假设检验自适应地检测分割点,以解决分割点难以确定的问题,并基于短期趋势修正分割点处的预测模型,减少了预测模型对缓冲数据的依赖.数值实验结果验证了本研究所提预测方法的有效性和可行性. 展开更多
关键词 离散数据流预测 在线数据流分割 非参数回归 趋势提取
下载PDF
Constructing a data platform for surface defect management using a multidimensional database
18
作者 SU Yicai OU Peng GAO Wenwu 《Baosteel Technical Research》 CAS 2013年第4期16-20,共5页
Surface quality has been one of the key factors influencing the ongoing improvement of the quality of steel. Therefore,it is urgent to provide methods for efficient supervision of surface defects. This paper first exp... Surface quality has been one of the key factors influencing the ongoing improvement of the quality of steel. Therefore,it is urgent to provide methods for efficient supervision of surface defects. This paper first expressed the main problems existing in defect management and then focused on constructing a data platform of surface defect management using a multidimensional database. Finally, some onqine applications of the platform at Baosteel were demonstrated. Results show that the constructed multidimensional database provides more structured defect data, and thus it is suitable for swift and multi-angle analysis of the defect data. 展开更多
关键词 surface defect multidimensional database data warehouse on-line analysis
下载PDF
A search for evidence of small-scale inhomogeneities in dense cores from line profile analysis
19
作者 Lev Pirogov 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第8期97-102,共6页
In order to search for intensity fluctuations on the HCN(1-0) and HCO+(1-0) line pro- files, which could arise due to possible small-scale inhomogeneous structure, long-term observations of high-mass star-forming... In order to search for intensity fluctuations on the HCN(1-0) and HCO+(1-0) line pro- files, which could arise due to possible small-scale inhomogeneous structure, long-term observations of high-mass star-forming cores S140 and S199 were carried out. The data were processed by the Fourier filtering method. Line temperature fluctuations that exceed the noise level were detected. Assuming the cores consist of a large number of randomly moving small thermal fragments, the total number of frag- ments is - 4 × 106 for the region with linear size - 0.1 pc in S140 and - 106 for the region with linear size - 0.3 pc in S 199. Physical parameters of fragments in S 140 were obtained from detailed modeling of the HCN emission in the framework of the clumpy cloud model. 展开更多
关键词 lineS profiles - molecular data - methods data analysis - ISM clouds - ISM molecules - ISM structure - ISM individual objects (S 140)
下载PDF
Data Intelligent Low Power High Performance TCAM for IP-Address Lookup Table
20
作者 K. Mathan T. Ravichandran 《Circuits and Systems》 2016年第11期3734-3745,共12页
This paper represents current research in low-power Very Large Scale Integration (VLSI) domain. Nowadays low power has become more sought research topic in electronic industry. Power dissipation is the most important ... This paper represents current research in low-power Very Large Scale Integration (VLSI) domain. Nowadays low power has become more sought research topic in electronic industry. Power dissipation is the most important area while designing the VLSI chip. Today almost all of the high speed switching devices include the Ternary Content Addressable Memory (TCAM) as one of the most important features. When a device consumes less power that becomes reliable and it would work with more efficiency. Complementary Metal Oxide Semiconductor (CMOS) technology is best known for low power consumption devices. This paper aims at designing a router application device which consumes less power and works more efficiently. Various strategies, methodologies and power management techniques for low power circuits and systems are discussed in this research. From this research the challenges could be developed that might be met while designing low power high performance circuit. This work aims at developing Data Aware AND-type match line architecture for TCAM. A TCAM macro of 256 × 128 was designed using Cadence Advanced Development Environment (ADE) with 90 nm technology file from Taiwan Semiconductor Manufacturing Company (TSMC). The result shows that the proposed Data Aware architecture provides around 35% speed and 45% power improvement over existing architecture. 展开更多
关键词 Low Power TCAM Switching Power Match line Searchline data Aware and Speech Processing
下载PDF
上一页 1 2 149 下一页 到第
使用帮助 返回顶部