Using self-location to calibrate the errors of observer positions for source localization

The uncertainty of observers＇ positions can lead to significantly degrading in source localization accuracy. This pa-per proposes a method of using self-location for calibrating the positions of observer stations in source localization to reduce the errors of the observer positions and improve the accuracy of the source localization. The relative distance measurements of the two coordinative observers are used for the linear minimum mean square error （LMMSE） estimator. The results of computer si-mulations prove the feasibility and effectiveness of the proposed method. With the general estimation errors of observers＇ positions, the MSE of the source localization with self-location calibration, which is significantly lower than that without self-location calibra-tion, is approximating to the Cramer-Rao lower bound （CRLB）.

Study on the method of optimal location on explosion events at near-source site

IntroductionEarthquake location is one of the inverse problems in seismology. The accurate earthquake source location is the basis of studies of earthquake images, the relation analysis between seismicity and tectonics, and the important parameters of earthquakes. It is also the basic data used to study the space distribution of aftershocks after a strong earthquake. The earthquake location accuracy mainly depends on reliability of the velocity models for the earth￠s crust, the reasonable design of the seismograph network, the accuracy of arrival time, and the location method used (ZHAO, 1983; ZHU, ZHAO, 1997; LI, et al, 1999). The reliability of the velocity model directly influences loca-tion results. The reasonable seismograph network design can improve the location accuracy; otherwise it will in-troduce ill-conditioned equations and large location error. If arrival time is not accurate, for example, if the seismic phase is wrongly identified or the time service is inaccurate, large arrival time error will be produced, and the location results and real hypocenters will be discordant. Different location algorithms adopted will produce differ-ent location errors. The residual criterion chosen has influence on location results. Besides, whether the event is correctly associated also influences the location quality. In practice, it can often be seen that large location devia-tion introduced by wrong event association.

γ- ray self-absorption of cylindrical fissile material

The self-absorption of γ-ray emitted from cylindrical fissile materials, such as 235 U and 239 Pu, does not possess spherical symmetry. The analytical formulae of self-absorption for γ-ray throughout the cylinder have been obtained. The intensity of γ-ray is a function of γ-ray outgoing directions and cylindrical configurations, accordingly one can acquire the information about geometrical configuration of cylindrical fissile materials through multi-location measurements. Further more, the method is given in this article. The result can be applied to the fissile material safe- guard, such as nuclear monitoring and verifying.

Comparison of two earthquake early warning location methods

According to earthquake catalog records of Fujian Seismic Network, the Tnow method and the fourstation continuous location method put forward by Jin Xing are inspected by using P-wave arrival information of the first four stations in each earthquake. It shows that the fourstation continuous location method can locate more seismic events than the Tnow method. By analyzing the results, it is concluded that the reason for this is that the Tnow method makes use of information from stations without being triggered, while some stations failed to be reflected in earthquake catalog because of discontinuous records or unclear records of seismic phases. For seismic events whose location results can be given, there is no obvious difference in location results of the two methods and positioning deviation of most seismic events is also not significant. For earthquakes outside the network, the positioning deviation may amplify as the epicentral distance enlarges, which may relate to the situation that the seismic stations are centered on one side of epicenter and the opening angle between seismic stations used for location and epicenter is small.

Development and Performance Evaluation of Self-Generating Enhanced Foam Water Plugging System

For the waterflooding of late development on an offshore oilfield has become worse, and some wells group has entered into high water cut-off period, water plugging work becomes particularly important. Due to the limited construction of offshore oilfield, space water supply difficulties, and stability of plugging agent, self-generating enhanced foam has been designed as the aimed block plugging system. The formula is determined as: 23.25% of NH4Cl + 30% of NaNO2 + 0.1% of catalyst + 0.6% of COSL-3 foaming agent + 0.25% of HS-type HPAM foam stabilizer. Measurement point of pipe with permeability of 0.5 μm2 and 2 μm2 has been used in the plugging and EOR experiments. The experiments show that this system has the selective plugging effect for the heterogeneous formation, especially for middle and posterior part of high permeability formation, and the recovery rate of low permeability pipe is enhanced up to 32.15%.

Parameter Self - Learning of Generalized Predictive Control Using BP Neural Network

This paper describes the self—adjustment of some tuning-knobs of the generalized predictive controller(GPC).A three feedforward neural network was utilized to on line learn two key tuning-knobs of GPC,and BP algorithm was used for the training of the linking-weights of the neural network.Hence it gets rid of the difficulty of choosing these tuning-knobs manually and provides easier condition for the wide applications of GPC on industrial plants.Simulation results illustrated the effectiveness of the method.

LOCATIONAL DISTRIBUTION AND SPATIAL DIFFUSION OF FOREIGN DIRECT INVESTMENTS FROM HONGKONG AND MACAO IN MAINLAND OF CHINA

Foreign direct investments (or FDIs) have been employed since the early 1980s and they have become more and more immportant in Chinese economic development. However, the roles of FDIs are very different between regions, partly due to the different locational preference of various source countries. Some facts show that FDIs from Hongkong - Macao indicate a strong locational preference. Therefore, this paper attempts to make an empirical research on the locational preference of Hongkong - Macao’s FDIs and their spatial diffusion under the support of statistical data with regrereion analysis. In this paper, three statistical models, including the special location model, the general location model and the spatial diffusion model, are created. The results show that this kind of analysis is successful. The major conclusions are as follows. (1) The optimum location for FDIs from Hongkong - Macao lies in the coastal area, especially Guangdong, Hainan, Jiangsu, Shandong, Fujian provinces. Besides, Hubei Province is also an important radon. (2) The FDIs from HongkongMacao in China have diffused gradually from the coastal provinces to the inland regions, the northem and the metropolis and from the locations that had attracted a large number of investments to their vicinities since the 1990s. (3) The special location factors, such as the herder effect, the unique social and kinship ties are the key factors determining the special locational distribution. (4) The general location and spatial diffusion of Hongkong - Macao’s FDIs are the results of interplay of several economic factors. They are the economic scale and advantage, the growth rate, the laier force and economic extrovert etc.

Self - Crosslinking Behavior of Self - Emulsion Water - Based Polyure-thane Coating Agents

The relation between structures and properties of polyurethane are investigated by modern physical and chemical methods.The results obtained are as follows:the effects of the content of self-crosslinking agent on the properties of polyurethane,i.e.,dispersion stability,dynamical viscoelasticity and mechanical properties are discussed.It is found that the optimum molar ratio of epichlorohydrin and diethylenetriamine is 1:2.A mois-

Culture Self- Consciousness in Transmission of Chinese Philosophy from the Perspective of English Globalization -- Taking the Belt and Road Initiative for Example

The Belt and Road Initiative contains the aspiration of Chinese nation to pursue ideological freedom and desire of strengthening international exchanges and cooperation. This paper takes the Belt and Road Initiative for example,emphasizing the interpretation of the inheritance and development of Chinese culture so as to study the importance of Culture Self-Consciousness in Chinese Philosophy,in the context of English globalization. That is to say,this paper stresses the spirits and the stand of nation 's demonstration on pursuing peace,cooperation and sustainable development in the civilization continuity from traditional China to the contemporary China,with practical philosophic view.

A Two-Station Passive Locating Solution Independent of the Baseline Length

The two-station positioning system based on time difference and azimuth measurement has measurement redundancy. Therefore, not only can a positioning solution which is completely independent of the baseline length between two stations be derived, but also the baseline length can be solved as an unknown quantity. These findings not only enhance the performance of the two-station positioning system, but also provide a design basis for the construction of a self-organizing dynamic intelligent positioning system.

An Identifier-Based Network Access Control Mechanism Based on Locator/Identifier Split

Legacy IP address-based access control has met many challenges, because the network nodes cannot be identified accurately based on their variable IP addresses. “Locator/Identifier Split” has made it possible to build a network access control mechanism based on the permanent identifier. With the support of “Locator/Identifier Split” routing and addressing concept, the Identifier-based Access Control (IBAC) makes net-work access control more accurate and efficient, and fits for mobile nodes’ access control quite well. Moreover, Self-verifying Identifier makes it possible for the receiver to verify the packet sender’s identity without the third part authentication, which greatly reduces the probability of “Identifier Spoofing”.

基于渐进式认知发现的新型配电网故障定位方法

在“双碳”目标下,持续接入分布式电源的新型配电网对运行可靠性提出了更高的要求,如何在渗透率变化的场景下提高现有故障定位方法的适应能力成为亟需解决的问题。为此,采用元学习特有的学会学习机制,提出了一种基于渐进式认知发现的新型配电网故障定位方法。首先,基于现有场景数据采用网络结构搜索算法构建当前场景个性化定位模型;然后,利用元学习算法提取模型构建过程中的知识因子,组成故障定位认知发现库;进而,在数据流和知识流的共同作用下,故障定位模型渐进地实现场景持续变化下的自主进化;最后,在PSCAD仿真平台对所提方法进行了验证。结果表明:所提方法具有定位精度高、鲁棒性强的优点,且在不同渗透率的故障场景下有着良好的泛化能力。研究结果可为基于人工智能的定位方法在实际系统中的应用提供技术支持。

自行火炮综合性维修保障设备的设计与实现

针对传统的自行火炮维修保障效率低、综合性差,功能单一,以某自行火炮为研究对象,研究设计了一种综合性维修保障设备。详细阐述了电气设备状态评估、故障诊断及基于历史数据自动履历管理的设计实现,该设备具有在线和离线2种使用方式,在自行火炮战备训练前、中、后提供保障。经验证,该综合性维修保障设备功能完善、故障定位快速准确、综合性强、人机交互性良好,对自行火炮维修保障设备的高质量发展具有重要意义。

无线传感器网络Range-free自身定位算法仿真分析

定位技术是无线传感器网络重要的支撑技术之一。文章在总结有关定位算法的文献和研究成果的基础上。介绍了6种代表性的Range-free定位算法的原理，在Matlab环境下构造了网络拓扑场景进行了仿真实验，对6种代表性算法的性能进行比较并分析总结，指出了今后无线传感器网络定位算法的研究中所需解决的问题。

基于Multi-agent的智能馈线自动化自愈控制

针对传统馈线自动化自愈控制技术实时性差、互动性弱、可靠性低的问题,提出了基于Multi-agent系统的智能馈线自动化自愈控制方法。主站和每个智能配电终端均作为1个Agent,各Agent通过通信网络组成1个Multi-agent系统。各Agent通过信息交互,利用改进的差动电流法实现故障定位,并利用启发式搜索算法,以停电负荷最少和馈线负荷均衡为故障恢复目标、以供电恢复路径的负荷度最小为搜索规则,实现故障恢复。通过电磁暂态仿真软件PSCAD对某实际配电网进行仿真,利用改进的差动电流法,中间支路和边界支路均能实现准确地故障定位;利用启发式搜索方法,能实现非故障失电区全部负荷的供电恢复,故障恢复效果与传统的遗传算法相当,但是故障恢复时间明显缩短且满足负荷均衡。仿真结果表明,该自愈控制方法能够实现准确地故障定位和快速地故障恢复,可以可靠地应用于智能配电网。

基于量子蚁群算法的配电网故障区段快速定位技术

分布式电源并入配电网已成为新型电力系统重要特征之一,分布式电源的接入与发电的不确定性使配电网潮流复杂多变,对配电网故障快速定位提出更高的技术要求.然而,现有智能优化算法在解决配电网故障区段定位问题时会出现收敛速度慢、易陷入局部最优等问题.针对这些挑战与问题,提出一种基于量子蚁群算法(QACA)的配电网故障区段快速定位技术.首先,根据状态逼近思想和最小故障集理论构建配电网故障定位的数学模型;其次,针对馈线终端单元上传信息缺失情况提出信息自修正方法,并提出分级定位模型来缩短定位时间;然后,提出3种改进技术对QACA进行针对性改进,改进量子旋转门更新机制,以函数控制形式动态调整旋转角大小,同时引入精英策略加快算法收敛速度.最后,在关键参数确定后验证了改进技术、信息自修正法、分级定位模型的有效性.将所提算法与7种不同算法进行对比,结果表明:改进的QACA可有效完成故障区段定位,具有良好的收敛速度、准确率以及容错性能.

基于改进神经网络的船舶航行速度估计数学模型

船舶航行速度直接影响船舶航行安全与路径规划效果,为此建立基于改进神经网络的船舶航行速度估计数学模型,提升船舶航行速度估计效果。利用位置编码机制,编码处理风速与波高等船舶航向速度相关数据;在编解码卷积神经网络内,引入自注意力机制,得到改进编解码卷积神经网络;利用编码后的船舶航速训练数据,训练改进神经网络,建立船舶航行速度估计数学模型;在该模型内,输入编码后的船舶航速测试数据,通过自注意力机制,提取船舶航速数据特征,并结合自注意力蒸馏剔除冗余特征;通过全连接层处理船舶航速数据特征,输出船舶航行速度估计结果。实验证明,该模型可有效提取船舶航速数据特征;该模型可精准估计船舶航行速度;在不同浪向下,该模型船舶航行速度估计的决定系数均较高,即估计精度较高。

无线传感器网络中基于DV-hop的一种改进算法

自身定位算法在无线传感器网络技术中的目标定位和跟踪等方面起着举足轻重的作用,算法的优劣直接影响着自身定位和目标定位的精度。提出了一种WDH(Weighted-DV-hop)定位算法,是以传统的DV-hop算法为依据,在获得跳数的步骤中,根据接收到的传播信号的区分强弱程度,取0.5或1作为跳数递增量的加权修正值,来得到新的跳数;通过Matlab平台的实现,验证该算法可以明显的提高定位的精度。

基于K-邻居节点覆盖的物联网定位模型

针对传统基于接收信号强度的定位缺陷,提出一种新型的基于K-邻居节点覆盖的物联网定位模型.该模型分为选取邻居节点与定位两个阶段,未知节点先通过调整发射功率等级来选择最近的K个邻居节点,尽量减少远距离节点对定位的影响.定位阶段,未知节点通过与K个信标节点的接收信号强度来计算权重,通过加权求和算出未知节点的坐标.采用K-邻居节点误差的自校正方法对坐标进行补偿.该定位模型可有效的避免环境因素对定位的影响,且定位算法简单,避免复杂的计算.实验表明,该定位模型定位精度较高.

基于DV-HOP算法的提高定位精度研究

无线传感器网络在目标追踪、环境监测到空间探索等方面得到广泛应用,其关键支撑技术之一是节点定位.以经典的DV-HOP算法为研究对象,为突破算法本身的计算应用条件限制,在使用最小二乘原理得到位置信息时,采用异方差消除原理,在参考节点位置信息存在明显误差时,提高未知节点的定位精度.仿真实验结果表明:与原算法相比,改进算法能够降低累积误差带来影响,定位精度明显提高.