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传感器网络
传感器网络由大量能量有限的微型传感器节点组成.因此,如何保证在足够覆盖监测区域的同时延长网络的寿命,是一个需要解决的重要问题.为了达到这一目标,一种广泛采用的策略是选出部分能够足够覆盖监测区域的节点作为工作节点,同时关闭其他冗余节点.提出了一个数学模型,使得只要已知监测范围和节点感知半径的比值,就可以计算出达到服务质量期望所需要的节点数量.需要指出的是:与大部分研究覆盖的文献不同,该研究不基于节点的位置信息,因此可以极大地降低硬件成本,并且减少节点获得和维护位置信息的开销.模拟实验结果表明:在随机部署条件下,服务质量期望与实验所得到的实际覆盖度的误差不大于服务质量期望的2% 而对于相同的服务质量期望和实际覆盖度,计算所得的工作节点数量与实验所得的工作节点数量的误差小于计算数量的5%,这表明推导出的节点数量与服务质量期望之间的关系与模拟实验的结果相吻合.该结果可以广泛应用于传感器网络的节点部署、拓扑控制等领域中.()
- 2008-03-22 23:09:53下载
- 积分:1
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hjk
itroduce hjk sensors and config it
- 2016-10-11 16:46:19下载
- 积分:1
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ReWorksReDe
ReWorks嵌入式实时操作系统和ReDe嵌入式软件开发环境(ReWorks ReDe)
- 2010-02-25 17:28:38下载
- 积分:1
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Real-time-detection-of-negative
同相牵引供电系统旨在实现电能质量的综合补偿。提出了一种基于同步坐标变换的电流检测方法,能实时准确地检测
出负载电流的基波正序有功分量、基波正序无功分量、基波负序分量以及谐波分量,为综合补偿提供了基础。电能质量的补
偿力度与设备容量之间存在非线性关系。提出补偿度的概念,并给出补偿度与电能质量参数的关系,通过给定电能质量期望
参数,实时调整负序、谐波以及无功补偿度,使得综合潮流控制器容量在各电能质量补偿参数之间得到实时优化配置,从而
实现同相供电系统容量优化满意补偿。理论推导和仿真结果验证了所提方法的正确性和可行性。(The cophase traction power supply system aims at achieving power quality comprehensive compensation.A current
detection method based on synchronous reference frame transformation is proposed.The method can decompose the load current
real-timely into fundamental positive-sequence active component,fundamental positive-sequence reactive component,fundamental
negative-sequence component and harmonic component,which lays a foundation for comprehensive compensation.There are
nonlinear relation between compensation strength of power quality and device capacity.The paper proposes the concept of
compensation degree and gives the relationship between compensation degree and power quality parameters.By giving expected
power quality parameters,it adjusts compensation ratios of negative,reactive and harmonics instantaneously,so that the IPFC
capacity can be allocated between power quality compensating parameters optimally and real-timely,thus achieving capacity optimal
satisfactory compensa)
- 2012-03-01 16:12:06下载
- 积分:1
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MEMS-based-spectrometer
一种基于MEMS技术的光谱仪系统介绍及发展情况介绍。(Introduce a systematic introduction and development of MEMS-based spectrometer.)
- 2012-08-09 17:23:13下载
- 积分:1
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JTXHFANGZHEN
本文在分析城市交通信号控制研究现状和交叉口交通信号控制原理、评价方
法的基础上,设计了单交叉口交通信号两级模糊控制系统。分级模糊控制能有效
减少模糊规则数,易于提取模糊规则,适合于交通状况复杂的城市交叉口交通信
号控制。但它存在难以由人工合理定义全部模糊隶属度函数的问题。为此本文进
一步采用遗传算法对两级模糊控制器中模糊隶属度函数进行优化。本文提出的方
法具有分级模糊控制的优点,同时可以使模糊隶属度的选取更为合理,获得更好
的控制效果。对一个四相位单交叉口,利用MATLAB在不同的交通条件下进行
了仿真,并利用交通仿真软件PARAMICS进行了可视化仿真。仿真结果表明该
方法能有效降低通行车辆在交叉口的平均等待时间,明显优于传统控制方法(After analyzing the city-traffic developments,the grade crossings control theory
its method of evaluation,the paper designs a traffic signal two-stage fuzzy control
tem for single intersection.Two-stage fuzzy controller,which is easy to acquire
zy rules and can greatly decrease the number of fuzzy rules,is very suitable to
plex urban intersection control.But it still presents a difficulty for deciding all the
bership functions correctly only by human experience.Therefor,to solve this
blem,a technique using genetic algorithm to modify its fuzzy membership
ctions is proposed.This method not only possesses the advantages of hierarchical
zy control,but also can change its membership functions adaptively to an optimal
ing in different traffic situations as well,and in this way the currency power of the
an intersection is improved.For a single urban intersection with four-phase,
ulation of different traffic condition is processed by using MATLAB.Moreover,
ble simulation is proce)
- 2009-12-07 22:30:53下载
- 积分:1
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Control-Strategy
。归纳和讨论了智能微电网的控制理论,将控制策略划分为电网跟随控制和电
网形成控制两大类,每一类同时又包含了交互式及非交互式控制思想,给出了清晰的定义和判断标准,
并提出智能微电网控制策略未来的发展方向。(Analysis was made to its system configuration
and operation characteristics, the control theory of intelligent microgrid summarized and discussed to divide the control
strategy into grid-following and grid-forming control two categories, each of which included interactive and non interactive control
thinking with clear definition and determinant standard. This paper raised the microgrid control strategy in the future.)
- 2012-07-16 21:10:26下载
- 积分:1
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optimized_datacenter_cloud
Towards an optimized abstracted topology design in cloud environment
- 2019-01-19 09:08:26下载
- 积分:1
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1
说明: 超紧耦合是 GPS/INS 组合导航系统的最新研究方向,它采用 INS 测得的载体动态信息辅助 GPS 接收机跟踪环
路,消除卫星信号中由于载体与卫星之间相对运动所产生的频率偏移,提高接收机在高动态环境下载波跟踪性能,同时还
可以压缩带宽,有效增强接收机抗干扰性能。介绍 GPS/INS 超紧耦合技术,给出 INS 辅助 GPS 载波跟踪环路结构图和相应
的数学模型,分析 INS 辅助 GPS 跟踪环路在动态环境下的动态残留及其对环路相位误差的影响,并进行了模型仿真,最后
对仿真结果进行了验证分析。仿真结果显示,辅助动态残留及其导致的环路相位误差的大小与加加速度、环路辅助时间间
隔成正比。
(The ultra-tightly coupled GPS/INS integrated navigation system latest research direction, it adopted the INS measured the carrier dynamic information auxiliary GPS receiver tracking loop to eliminate the satellite signal frequency due to the relative motion between the carrier and the satellite offset improve the receiver in high dynamic environment download wave tracking performance, but also can compress bandwidth, effectively enhance the anti-jamming performance of the receiver. Introduced GPS/INS ultra-tight coupling technology gives INS assisted GPS carrier tracking loop diagram and the corresponding mathematical model to analyze the impact of the INS assisted GPS tracking loop dynamic residues in a dynamic environment and the loop phase error, and model simulation, and analysis of simulation results verified. Simulation results show that the the residual secondary dynamic its resulting size of the error loop phase and jerk loop secondary is proportional to the time interval.)
- 2012-12-05 07:26:57下载
- 积分:1
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SAR
说明: SAR图像斑点噪声抑制方法与应用研究,里面给出里处理Sar
影像的算法(SAR image speckle noise reduction methods and applied research, which is given to deal with Sar Imaging Algorithm)
- 2008-12-04 16:43:54下载
- 积分:1