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基于无传感器信息的数控机床伺服进给系统性能评估研究 被引量:4
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作者 周玉清 梅雪松 《机械工程学报》 EI CAS CSCD 北大核心 2012年第20期32-32,共1页
无传感器测试是相对于加速度、切削力、声发射、球杆仪等外置传感器信息采集、分析的一。种策略,即深入研究数控机床伺服控制系统内置的电机编码器、光栅尺、电机伺服驱动器霍尔电流传感器等测试元件所提供的信息,通过合理规划测试路... 无传感器测试是相对于加速度、切削力、声发射、球杆仪等外置传感器信息采集、分析的一。种策略,即深入研究数控机床伺服控制系统内置的电机编码器、光栅尺、电机伺服驱动器霍尔电流传感器等测试元件所提供的信息,通过合理规划测试路径进行激励,并结合基于先进的信号数据处理方法,对伺服进给系统动态性能进行评估。 展开更多
关键词 伺服进给系 统性能评估 无传感器 信息采集 数控机床 霍尔电流传感器 伺服控制系 数据处理方法
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卫星数字电视接收站的工程设计、调测和系统性能评估(17)
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作者 杨尧生 苏泉 杨栋 《有线电视技术》 2003年第20期23-28,共6页
5.4.2技术性能评估 如前所述,技术性能评估是要通过测试,看一下站址选择是否合理,设计是否正确,调试是否准确无误,进而通过测试数据计算卫星数字接收站的年平均可用度,年平均不可用时间.
关键词 卫星数字电视 接收站 工程设计 调测 统性能评估 上行链路
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卫星数字电视接收站的工程设计、调测和系统性能评估(4)
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作者 杨尧生 苏泉 杨栋 《有线电视技术》 2003年第7期37-42,共6页
2.1.3 上、下行链路中的干扰噪声 卫星数字电视接收站的噪声除上、下行链路线性器件内部产生的热噪声外,还有一部分是上、下行链路的干扰噪声.由于落在噪声带宽内的各种干扰功率的总和Nltol可以假想成一个噪声温度为Tltol噪声源产生,Nlt... 2.1.3 上、下行链路中的干扰噪声 卫星数字电视接收站的噪声除上、下行链路线性器件内部产生的热噪声外,还有一部分是上、下行链路的干扰噪声.由于落在噪声带宽内的各种干扰功率的总和Nltol可以假想成一个噪声温度为Tltol噪声源产生,Nltol=KTltolBn,k为波尔兹曼常数.这样这些干扰噪声也可以当成热噪声一样处理.如果对这一部分噪声不了解,进而在工程估算中略去它们,有时可能会使工程估算的结果和实际测量结果产生较大的偏差. 展开更多
关键词 卫星数字电视 接收站 工程设计 调测 统性能评估 干扰噪声 行波管 上下行路链路
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基于生物膜的零换水淡水异足新米虾养殖系统性能评估
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《渔业现代化》 北大核心 2016年第5期78-78,共1页
在一个室内水族馆中使用一个零换水系统评价了生物膜对水质以及作为一种食物来源对淡水异足新米虾的养殖所做出的贡献.进行了生物膜的两个连续生长阶段试验,以针对在不同基质(聚乙烯网PN、塑料瓶PET和agrovelo,AV)上生物膜的形成及其... 在一个室内水族馆中使用一个零换水系统评价了生物膜对水质以及作为一种食物来源对淡水异足新米虾的养殖所做出的贡献.进行了生物膜的两个连续生长阶段试验,以针对在不同基质(聚乙烯网PN、塑料瓶PET和agrovelo,AV)上生物膜的形成及其对淡水虾养殖的影响进行评价.生物膜在所有基质上的生长因其对氮化物的吸收、因与自养微生物繁殖相关的溶氧的高产出而有助于维持一个良好的水质. 展开更多
关键词 生物膜 虾养殖 统性能评估 淡水 换水 微生物繁殖 阶段试验 食物来源
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“重庆电网智能二次系统性能评估及工程应用”研究成果达国际先进水平
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《内蒙古电力技术》 2012年第3期39-39,共1页
2012-05—30,重庆电力科学试验研究院承担完成的!重庆电网智能二次系统性能评估及工程应用”研究成果顺利通过鉴定,鉴定委;员会一致认为该成果处于国际先进水平。
关键词 统性能评估 研究成果 重庆 进水 国际 应用 工程 智能
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澳大利亚性能化设计评估方法 被引量:2
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作者 李国辉 《消防科学与技术》 CAS 北大核心 2016年第6期747-747,共1页
澳大利亚设有防火规范改革中心,并发布了《消防工程指南》,该指南提出了性能化设计规范的要求,并提出了一套三级消防工程系统评估方法。第一级为系统等价性评估,适用于评估消防系统的局部运行性能;第二级为系统性能评估,用于分析... 澳大利亚设有防火规范改革中心,并发布了《消防工程指南》,该指南提出了性能化设计规范的要求,并提出了一套三级消防工程系统评估方法。第一级为系统等价性评估,适用于评估消防系统的局部运行性能;第二级为系统性能评估,用于分析整个消防系统中各子系统的相互作用,选择具有代表性的火灾场景,保证系统符合规定的安全要求;第三级为系统风险性评估,用于评估大型综合建筑或有创意的其他建筑,结合各种措施对总体安全性作出评估。 展开更多
关键词 评估方法 性能化设计 澳大利亚 工程系 消防工程 消防系 综合建筑 统性能评估
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A Study on Interoperability for Systems Operating in VHF/UHF Bands with Geographic Information
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作者 Jeong-Seok Jang Kyoung-Whoan Suh 《通讯和计算机(中英文版)》 2012年第11期1279-1286,共8页
关键词 地理信息系 UHF频段 互操作性 VHF 统性能评估 频率偏移 最小耦合损耗 无线系
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重庆电科院一项目成果达国际先进水平
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《电气技术》 2012年第6期72-72,共1页
近日重庆电力科学试验研究院承担完成的"重庆电网智能二次系统性能评估及工程应用"研究成果经市科委鉴定,处于国际先进水平,首次构建了智能变电站系统级测试方法。
关键词 重庆 进水 国际 统性能评估 研究成果 科学试验 测试方法 电站系
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Attack Resistant Trust Management Model Based on Beta Function for Distributed Routing in Internet of Things 被引量:1
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作者 Dong Ping Guan Jianfeng +1 位作者 Xue Xiaoping Wang Hongchao 《China Communications》 SCIE CSCD 2012年第4期89-98,共10页
With the rapid development of Internet of Things (IoT),the issue of trust in distributed routing systems has attracted more research attention.The existing trust management frameworks,however,suffer from some possible... With the rapid development of Internet of Things (IoT),the issue of trust in distributed routing systems has attracted more research attention.The existing trust management frameworks,however,suffer from some possible attacks in hostile environments,such as false accusation,collusion,on-off,and conflicting behavior.Therefore,more comprehensive models should be proposed to predict the trust level of nodes on potential routes more precisely,and to defeat several kinds of possible attacks.This paper makes an attempt to design an attack-resistant trust management model based on beta function for distributed routing strategy in IoT.Our model can evaluate and propagate reputation in distributed routing systems.We first describe possible attacks on existing systems.Our model is then proposed to establish reliable trust relations between self-organized nodes and defeat possible attacks in distributed routing systems.We also propose a theoretical basis and skeleton of our model.Finally,some performance evaluations and security analyses are provided to show the effectiveness and robustness of our model compared with the existing systems. 展开更多
关键词 trust management IOT distributed ROUTING PROBABILITY
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Coupled simulation of BES-CFD and performance assessment of energy recovery ventilation system for office model 被引量:5
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作者 Yunqing FAN T.Hayashi K.Ito 《Journal of Central South University》 SCIE EI CAS 2012年第3期633-638,共6页
Thermal comfort and indoor air quality as well as the energy efficiency have been recognized as essential parts of sustainable building assessment. This work aims to analyze the energy conservation of the heat recover... Thermal comfort and indoor air quality as well as the energy efficiency have been recognized as essential parts of sustainable building assessment. This work aims to analyze the energy conservation of the heat recovery ventilator and to investigate the effect of the air supply arrangement. Three types of mixing ventilation are chosen for the analysis of coupling ANSYS/FLUENT (a computational fluid dynamics (CFD) program) with TRNSYS (a building energy simulation (BES) software). The adoption of mutual complementary boundary conditions for CFD and BES provides more accurate and complete information of indoor air distribution and thermal performance in buildings. A typical office-space situated in a middle storey is chosen for the analysis. The office-space is equipped with air-conditioners on the ceiling. A heat recovery ventilation system directly supplies flesh air to the office space. Its thermal performance and indoor air distribution predicted by the coupled method are compared under three types of ventilation system. When the supply and return openings for ventilation are arranged on the ceiling, there is no critical difference between the predictions of the coupled method and BES on the energy consumption of HVAC because PID control is adopted for the supply air temperature of the occupied zone. On the other hand, approximately 21% discrepancy for the heat recovery estimation in the maximum between the simulated results of coupled method and BES-only can be obviously found in the floor air supply ventilation case. The discrepancy emphasizes the necessity of coupling CFD with BES when vertical air temperature gradient exists. Our future target is to estimate the optimum design of heat recovery ventilation system to control CO2 concentration by adjusting flow rate of flesh air. 展开更多
关键词 building energy simulation computational fluid dynamics (CFD) FLUENT TRNSYS energy saving
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Performance Analysis for Multimedia Communication Systems with a Multilayer Queuing Network Model 被引量:1
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作者 Xuehua Tang Zhongyuan Wang +3 位作者 Xiaojun Li Zhen Han Zheng He Youming Fu 《China Communications》 SCIE CSCD 2018年第8期67-76,共10页
Software performance evaluation in multimedia communication systems is typically formulated into a multi-layered client-server queuing network(MLCSQN) problem. However, the existing analytical methods to MLCSQN model ... Software performance evaluation in multimedia communication systems is typically formulated into a multi-layered client-server queuing network(MLCSQN) problem. However, the existing analytical methods to MLCSQN model cannot provide satisfactory solution in terms of accuracy, convergence and consideration of interlocking effects. To this end, this paper proposes a heuristic solving method for MLCSQN model to boost the performance prediction of distributed multimedia software systems. The core concept of this method is referred to as the basic model, which can be further decomposed into two sub-models: client sub-model and server sub-model. The client sub-model calculates think time for server sub-model, and the server sub-model calculates waiting time for client sub-model. Using a breadthfirst traversal from leaf nodes to the root node and vice versa, the basic model is then adapted to MLCSQN, with net sub-models iteratively resolved. Similarly, the interlocking problem is effectively addressed with the help of the basic model. This analytical solver enjoys advantages of fast convergence, independence on specific average value analysis(MVA) methods and eliminating interlocking effects.Numerical experimental results on accuracy and computation efficiency verify its superiority over anchors. 展开更多
关键词 multimedia communication system queuing network performance evaluation
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Stochastic Dynamic Modeling of Rain Attenuation: A Survey 被引量:1
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作者 Zhicheng Qu Gengxin Zhang +1 位作者 Haotong Cao Jidong Xie 《China Communications》 SCIE CSCD 2018年第3期220-235,共16页
Satellite communication systems(SCS) operating on frequency bands above 10 GHz are sensitive to atmosphere physical phenomena, especially rain attenuation. To evaluate impairments in satellite performance, stochastic ... Satellite communication systems(SCS) operating on frequency bands above 10 GHz are sensitive to atmosphere physical phenomena, especially rain attenuation. To evaluate impairments in satellite performance, stochastic dynamic modeling(SDM) is considered as an effective way to predict real-time satellite channel fading caused by rain. This article carries out a survey of SDM using stochastic differential equations(SDEs) currently in the literature. Special attention is given to the different input characteristics of each model to satisfy specific local conditions. Future research directions in SDM are also suggested in this paper. 展开更多
关键词 stochastic dynamic modeling rainattenuation time-series synthesizer satellitecommunication satellite link stochastic dif-ferential equations
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MODEL-BASED PERFORMANCE EVALUATION APPROACH FOR MOBILE AGENT SYSTEMS
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作者 LiXin MiZhengkun MengXudong 《Journal of Electronics(China)》 2004年第2期145-151,共7页
Claimed as the next generation programming paradigm, mobile agent technology has attracted extensive interests in recent years. However, up to now, limited research efforts have been devoted to the performance study o... Claimed as the next generation programming paradigm, mobile agent technology has attracted extensive interests in recent years. However, up to now, limited research efforts have been devoted to the performance study of mobile agent system and most of these researches focus on agent behavior analysis resulting in that models are hard to apply to mobile agent systems. To bridge the gap, a new performance evaluation model derived from operation mechanisms of mobile agent platforms is proposed. Details are discussed for the design of companion simulation software, which can provide the system performance such as response time of platform to mobile agent. Further investigation is followed on the determination of model parameters. Finally comparison is made between the model-based simulation results and measurement-based real performance of mobile agent systems. The results show that the proposed model and designed software are effective in evaluating performance characteristics of mobile agent systems. The proposed approach can also be considered as the basis of performance analysis for large systems composed of multiple mobile agent platforms. 展开更多
关键词 Mobile agent technology Performance evaluation System modeling Software simulation
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Long Term Assessment of a Grid Connected Solar PV System in Sydney 被引量:2
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作者 Saad Odeh 《Journal of Energy and Power Engineering》 2016年第10期591-599,共9页
This paper assesses 4 years of operation of a 1.75 kW roof top solar PV system installed in a Sydney suburban house. The system consists of 10 PV panels, a DC/AC inverter, and a grid connected gross meter. Solar elect... This paper assesses 4 years of operation of a 1.75 kW roof top solar PV system installed in a Sydney suburban house. The system consists of 10 PV panels, a DC/AC inverter, and a grid connected gross meter. Solar electricity delivered to grid is verified with the results from a computer simulation package (PVSYST) by adopting the installed component specifications, operation conditions, and weather data of the site. The results show high consistency between the values of energy delivered to the grid measured by the energy company and the energy estimated by system simulation. New system performance indicator is developed and called the optimum performance compliance ratio (PCR). It is a measure of the compliance of the output of the designed PV system with the output which would be produced by the same system with a solar tracker. This indicator provides system designers, contractors and energy providers with the actual capacity of the system that they can offer the end-users. 展开更多
关键词 Long term assessment grid connected PV system solar electricity performance indicator.
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Studies on TOP executive performance evaluation system of Chinese listed companies
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作者 王德武 姜国庆 +1 位作者 姜硕 HUANG Allen R 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2004年第6期671-674,共4页
According to the development status of Chinese listed companies, it is important to implement a stock option incentive plan for the top executives (TE) of the companies. It is necessary to establish a set of indices t... According to the development status of Chinese listed companies, it is important to implement a stock option incentive plan for the top executives (TE) of the companies. It is necessary to establish a set of indices to evaluate a top executive’s performance and award performance-based stock options to them scientifically and reasonably. This thesis sets indices from the perspective of the top executive’s behaviour and results, which differs from the traditional methods performance evaluation. 展开更多
关键词 performance evaluation indices set behaviour and result
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Modelling of Chillers for Energy Performance Assessment of HVAC Systems
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作者 Luigi Schibuola Massimiliano Scarpa Chiara Tambani 《Journal of Energy and Power Engineering》 2014年第6期1012-1020,共9页
The reliable assessment of the annual energy demand has become necessary in view of building energy performance certification. Accurate models must be used to simulate the behaviour of HVAC (heating, ventilation and ... The reliable assessment of the annual energy demand has become necessary in view of building energy performance certification. Accurate models must be used to simulate the behaviour of HVAC (heating, ventilation and air conditioning) components in real operation, usually characterized by a wide variation of building loads. In this context, this paper deals with the development and validation of an algorithm aimed at the assessment of part load performance of various kinds of controls for vapour compresion based heat pumps and chillers, in particular referring to on-off, inverter-driven and multi-stage vapour compression. The reliability of this algorithm in the calculation of seasonal performances is checked against monitoring of heat pumps and chillers operating under real conditions. 展开更多
关键词 MODELLING CHILLER part load energy performance building certification.
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The European New Car Assessment Programme: A historical review 被引量:4
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作者 Michiel van Ratingen Aled Williams +5 位作者 Anders Lie Andre Seeck Pierre Castaing Reinhard Kolke Guido Adriaenssens Andrew Miller 《Chinese Journal of Traumatology》 CAS CSCD 2016年第2期63-69,共7页
Established in 1997, the European New Car Assessment Programme (Euro NCAP) provides consumers with a safety performance assessment for the majority of the most popular cars in Europe. Thanks to its rigorous crash te... Established in 1997, the European New Car Assessment Programme (Euro NCAP) provides consumers with a safety performance assessment for the majority of the most popular cars in Europe. Thanks to its rigorous crash tests, Euro NCAP has rapidly become an important driver safety improvement to new cars. After ten years of rating vehicles, Euro NCAP felt that a change was necessary to stay in tune with rapidly emerging driver assistance and crash avoidance systems and to respond to shifting priorities in road safety. A new overall rating system was introduced that combines the most important aspects of vehicle safety under a single star rating. The overall rating system has allowed Euro NCAP to continue to push for better fitment and higher performance for vehicles sold on the European market. In the coming years, the safety rating is expected to play an important role in the support of the roll-out of highly automated vehicles. 展开更多
关键词 European New Car Assessment ProgrammeVehicle safetySafety ratingCrash testing
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