不依赖位置坐标的室内Wi-Fi网络覆盖度量方法

3GPP在版本16(R16,Release 16)中升级了最小化路测(MDT,minimization of drive test)技术,提出移动终端可利用4G/5G网络自主上报Wi-Fi信号的接收信号强度指示(RSSI,received signal strength indicator),为运营商度量Wi-Fi网络的覆盖率带来了可能性。然而,现有基于MDT技术的网络覆盖度量方法严重依赖GPS提供的位置坐标,但全球定位系统(GPS,global positioning system)不能提供室内精准定位,无法用于室内Wi-Fi网络的覆盖度量。为此,提出了一种不依赖位置坐标的RSSI聚类方法,充分利用室内相近位置RSSI的统计相似性,区分不同位置的RSSI测量差异,在无位置坐标条件下准确估计出室内Wi-Fi网络的覆盖率。实验结果表明,所提方法估计的覆盖率与基于真实位置坐标测量的覆盖率相近,度量准确度明显优于现有的其他方法。

Experimental study on the seismic behavior of high strength concrete fi lled double-tube columns

To study the seismic behavior of high strength concrete fi lled double-tube(CFDT) columns,each consisting of an external square steel tube and an internal circular steel tube,quasi-static tests on eight CFDT column specimens were conducted.The test variables included the width-to-thickness ratio(β1) and the area ratio(β2) of the square steel tube,the wall thickness of the circular steel tube,and the axial force(or the axial force ratio) applied to the CFDT columns.The test results indicate that for CFDT columns with a square steel tube with β1 of 50.1 and 24.5,local buckling of the specimen was found at a drift ratio of 1/150 and 1/50,respectively.The lateral force-displacement hysteretic loops of all specimens were plump and stable.Reducing the width-to-thickness ratio of the square steel tube,increasing its area ratio,or increasing the wall thickness of the internal circular steel tube,led to an increased fl exural strength and deformation capacity of the specimens.Increasing the design value of the axial force ratio from 0.8 to 1.0 may increase the fl exural strength of the specimens,while it may also decrease the ultimate deformation capacity of the specimen with β1 of 50.1.

Study on the crustal stress fi eld of the Tengchong volcanic area using composite focal mechanism method

We calculated the crustal stress field using the composite focal mechanism method based on the P-wave initial motion polarity data of the Tengchong volcanic area from January 2011 to April 2019 obtained from the Bulletin of Seismological Observations of Chinese stations.The magnitude range of earthquakes used in this study is 0–4,and their magnitudes are mainly approximately 1.0.To investigate the infl uence of the source location on the stress fi eld and obtain reliable stress fi elds of the study area,we applied the double-diff erence algorithm to relocate the seismic events,obtaining more accurate and reliable relative positions of seismic events with a clearer seismic belt.On the basis of relocation results,the study on the stress fi eld along the fault zone was conducted,and the infl uence of seismic event position on the stress fi eld was analyzed.Results show that,fi rst,the current stress regime in the shallow crust of the Tengchong volcanic area is strike-slip faulting,the orientation of the principal compressive stress axis is NE–SW,the orientation of the principal extension stress axis is SE–NW,the principal compressive and extension stress axes are nearly horizontal,and the dip angle of intermediate principal stress axis is relatively large.This reflects that the volcanic and seismic activities in the Tengchong volcanic area are mainly controlled by the collision and squeezing eff ect of the Indian–Eurasian plate.It also refl ects that the current tensile action caused by deep magma activity has little infl uence on the shallow crustal stress field.Second,the stress field along fault zones reveals that there exist local stress fi elds,such as the thrust stress regime at the strike-slip fault terminal area,which is consistent with the compressional area at the intersection of conjugate strike-slip faults indicated by previous study.Third,the stress fi eld results are consistent,regardless of using the original location in the bulletin or the relocated location,indicating that the infl uence of the event location error can be neglected when there are suffi cient data and refl ecting the stability of the composite focal mechanism method.The findings can serve as a reference for investigating geological structure movement,seismic activities,and volcanic activities in the Tengchong volcanic area.

Fast 3D forward modeling of the magnetic field and gradient tensor on an undulated surface

Magnetic field gradient tensor technique provides abundant data for delicate inversion of subsurface magnetic susceptibility distribution. Large scale magnetic data inversion imaging requires high speed and accuracy for forward modeling. For arbitrarily distributed susceptibility data on an undulated surface, we propose a fast 3D forward modeling method in the wavenumber domain based on(1) the wavenumber-domain expression of the prism combination model and the Gauss–FFT algorithm and(2) cubic spline interpolation. We apply the proposed 3D forward modeling method to synthetic data and use weighting coefficients in the wavenumber domain to improve the modeling for multiple observation surfaces, and also demonstrate the accuracy and efficiency of the proposed method.

Vertical derivative conversion of irregular-range potential fi eld data based on improved projection onto convex sets method

Gravity and magnetic exploration areas are usually irregular,and there is some data defi ciency.Missing data must be interpolated before the vertical derivative conversion in the wavenumber domain.Meanwhile,for improved processing precision,the data need to be edge-padded to the length required by the fast Fourier transform algorithm.For conventional vertical derivative conversion of potential fi eld data(PFD),only vertical derivative conversion is considered,or interpolation,border padding,and vertical derivative conversion are executed independently.In this paper,these three steps are considered uniformly,and a vertical derivative conversion method for irregular-range PFD based on an improved projection onto convex sets method is proposed.The cutoff wavenumber of the filter used in the proposed method is determined by fractal model fi tting of the radial average power spectrum(RAPS)of the potential fi eld.Theoretical gravity models and real aeromagnetic data show the following:(1)The fitting of the RAPS with a fractal model can separate useful signals and noise reasonably.(2)The proposed iterative method has a clear physical sense,and its interpolation,border padding error,and running time are much smaller than those of the conventional kriging and minimum curvature methods.

Three-dimensional numerical simulation of geothermal fi eld in space-wavenumber domain

Large-scale,fine,and efficient numerical simulation of a geothermal field plays an important role in geothermal energy development.Confronted with the problem of large computation and high storage requirements for complex underground models in a three-dimensional(3-D)numerical simulation of a geothermal fi eld,a mixed space-wavenumber domain 3-D numerical simulation algorithm is proposed in this paper.According to the superposition principle of temperature field,the geothermal field is decomposed into background and abnormal temperature fi elds for calculation.The uniform layered model is used to solve the background field.When the abnormal field is solved,the horizontal two-dimensional(2-D)Fourier transform is used to transform the 3-D diff erential equation satisfi ed by an abnormal field into a series of one-dimensional ordinary differential equations with diff erent wavenumbers,which greatly reduces the calculation and storage.The unit division of an ordinary diff erential equation is fl exible,and the calculation amount is small.The algorithm fully takes advantage of the effi ciency of the Fourier transform and the quickness of the catch-up method to solve linear equations with a fixed bandwidth,which effectively improves the computational efficiency.Compared with the COMSOL Multiphysics professional simulation finite element software,the time consumption and memory requirements of the algorithm proposed in this paper are reduced by multiple orders of magnitude in terms of ensuring accuracy and the same mesh division.The more the number of calculated nodes is,the more obvious is the advantage.We design models to study the thermal conductivity,heat fl ux boundary,regional tectonic morphology,and topographic relief of the geothermal fi eld distribution.A 3-D geophysical model is developed based on topographic elevation data,geothermal geology,and geophysical exploration data in the Qiabuqia area of Gonghe Basin,Qinghai Province,China.Numerical simulation of the geothermal fi eld in this area is realized,which shows that the algorithm is suitable for precise and effi cient simulation of an arbitrary complex terrain and geological conditions.

High-precision downward continuation of potential fi elds algorithm utilizing adaptive damping coeffi cient of generalized minimal residuals

The downward continuation of potential fields is a process of calculating their values in a lower plane based on those of a certain plane.This technology is not only a data processing method for resource exploration but also plays an extremely important role in military applications.However,the downward continuation of potential fields is a typical linear inverse problem that is ill-posed.Generalized minimal residuals(GMRES)is an eff ective solution to ill-posed inverse problems,but it is unstable under the condition wherein the GMRES is directly applied in the calculation process.Moreover,the long-term behavior of its iterative computation is a disordered,divergent result.Therefore,to obtain stable solutions,GMRES is applied to solve the normal equations of the downward continuation of potential fields;it is also used to prequalify for occasional interruptions in the operation process by adding the damping coefficient,thus strengthening the stability conditions of the equations of residual minimization.Finally,the stable downward continuation of the potential fields method is proposed.As indicated by the theoretical data and the measured testing data,the method proposed in this paper has the advantages of high-precision and excellent stability.Furthermore,compared with the Tikhonov iteration method,the proposed method avoids the need to choose regularization parameters.

离散度WKNN位置指纹Wi-Fi定位算法

为改善加权K近邻位置指纹定位算法在室内环境复杂时的定位性能,提出一种以位置指纹离散度作为权值参考的改进加权K近邻位置指纹定位算法.算法在离线位置指纹数据库建立阶段采用K-means聚类算法对位置指纹进行聚类,来降低搜索位置指纹库的计算量.从离线位置指纹库中选取K个与在线实测Wi-Fi信号强度信息最相似的位置指纹,比较其离散程度,将离散程度小的位置指纹赋予较高的加权系数,以减小原加权K近邻算法在室内复杂环境信号强度随距离变化较大情况下带来的位置估算误差.对离散度加权K近邻算法时间复杂度的分析表明,其计算量小于原加权K近邻算法;实际环境实验结果表明,离散度加权K近邻算法具有更高的定位精度,且定位误差波动较小.

基于聚类的快速Wi-Fi定位算法

Wi-Fi定位中用户移动终端计算能力差,提供的能量有限。为此,提出一种基于信号强度聚类的快速定位算法,依据接收信号强度的相似度对参考点分组再定位,从而减少定位计算量,提高Wi-Fi定位精度。在校园和市内2种不同室外环境下进行现场实验,数据显示定位均方根误差从16.71 m减小到9.68 m,定位时间从96.3 ms减小到5.2 ms,验证了该算法的高效性和有效性。

一种基于Wi-Fi信号指纹的楼宇内定位算法

由于GPS无法在楼宇内使用,而目前的楼宇内定位技术一般都需要预先部署额外的设施,因此楼宇内无基础设施定位成为了一个热点研究问题.提出了一种利用Wi-Fi接入点的MAC地址和RSSI(received signal strength indication)值,通过机器分类的方式实现楼宇内房间级定位的算法R-kNN(relativity k-nearest neighbor).R-kNN是一种属性加权k近邻算法,它通过将AP之间的相关性反应在权值的分配上,有效地降低了维度冗余对分类准确率的负面影响.R-kNN没有对房间和AP的物理位置做出任何假设,只需要使用环境中现存的AP就可以取得较好的定位效果,无需部署任何额外设施或修改现有设施.实验结果表明,在AP数量较多的楼宇环境中,R-kNN能够取得比k近邻算法和朴素贝叶斯分类器更好的定位效果.

合理成功预期对创造性判断的影响

我国司法实践中,最高人民法院法官多次通过合理预期来判断是否具有改进动机以作为判决的裁判要旨。BSH家用电器案、蔡艺斌案中,法官均认为当合理预期引入到该方案能够成功解决技术问题或满足达到的效果,则技术人员有动机去对现有技术进行这样的改进。文章通过分析一个二审案例得出创造性判断实践中存在未应用合理成功预期的问题,并进一步对合理成功预期标准不一的原因进行了剖析,同时,通过横向比较、借鉴美国、欧洲合理成功预期的法律规定和实践,提出客观合理成功预期的方法,并尝试对进一步完善《专利审查指南》提出建议。

一种基于WiFi的改进型室内位置指纹定位方法

在室内Wi Fi位置指纹定位系统中,由于室内环境的复杂性及易变性,定位精度很难得到保证。通过实验测试分析人体对Wi Fi信号的影响以及不同位置设备接入点数目的变化情况,本文提出一种在手持设备的定位系统中增加位置指纹特征以提高定位精度的改进型定位方法。该方法将手持设备的方向角和接入点数目这2个位置特征加入位置指纹中,丰富了离线数据库的位置特征。通过对常规位置指纹库定位和改进的位置指纹库定位的测试对比,得出使用改进的位置指纹库定位可以提高系统的定位精度的结论。

广域电磁法异常分离技术探索研究

如何有效地压制区域背景场,提取局部异常场加以分析,是广域电磁法提升资料处理和解释准确度亟待解决的问题之一。本文借鉴重磁勘探区域场分离的基本思想提出一种基于残差法的异常分离技术,既能有效地压制区域背景场,又能很好地突出反演成像中的断层、薄层等局部异常的有效信息,有效弥补了传统解释方法的不足。该方法以插值切割法为理论基础,提出了动态改进型插值切割算子,得到区域背景场,实现局部异常场与区域背景场的分离。设计了一维、二维复杂地电模型进行正演计算、反演成像和异常分离,证明了采用异常分离技术提取的局部异常信息对地层、构造和断裂的刻画更加精细,明显优于传统处理成果。使用该方法对川南长宁地区广域电磁法反演成像进行异常分离,进一步验证了异常分离成果反映的构造、薄层及断层等局部信息与地震剖面吻合度较高,表明本文提出的异常分离技术有效、可靠,能有效提升传统广域电磁法的反演成像精度和解释可靠度,具有重要的应用价值。

场域理论视角下“家校社”协同推进以体育人研究

运用文献资料、实地调研、逻辑分析等方法,探究场域理论视角下“家校社”协同推进以体育人的价值、困境,并提出路径。价值:延展育人空间,协调育人资源,整合育人理念。困境:场域的开放性有待提升,育人效能尚未充分发挥;资本的均衡性亟须优化,育人手段受到限制约束;惯习的灵活性有待增强,育人活力难以完全释放。路径:建立开放交流的三方协同体系,将家庭作为学校和社会的重要纽带,建立灵活有效的反思和反馈机制。

贵州省某废渣场环境管控方案之封场设计方案初探

以贵州省某废渣场为例,结合《危险废物填埋污染控制标准》(GB 18598—2019)的要求对该废渣场的封场设计方案进行了分析。并从工程建设及实际条件出发,通过终场覆盖系统中防渗层的选择与确定。制定了针对废渣场封场设计方案,可为今后的类似项目封场方案设计提供借鉴与参考。

室内WI-FI基于余弦匹配算法的研究与实现

由于传统定位技术用在室内定位的局限性,文中提出了室内基于WI-FI的余弦匹配定位算法。首先检测周围四个路由器发出WI-FI的信号强度,再采用余弦匹配,使用云计算计算出数据结构进而排序余弦匹配程度,最后将前几个余弦匹配值作为相对距离,并使用最小二乘法计算出相对于四个最强余弦匹配WI-FI的信号强度的相对距离从而得到最终坐标,并用于基于云计算可视化购物导航项目中,实用结果表明该算法的定位精度较高。

中苏在西伯利亚地区的戏剧艺术合作

中苏在戏剧艺术领域合作的历史是两个国家文化交流的重要领域。以苏联西伯利亚地区为例,笔者所依据的史料来自俄罗斯档案基金会及各类期刊和杂志。中俄人民对彼此艺术的了解始于沙俄和晚晴时期,1917年革命后,两个民族在戏剧艺术领域的交流开始不断加强,这股潮流在(苏联)远东地区和(中国)东北地区及两国首都城市率先兴起。在中俄关系中西伯利亚地区占据重要的跨境地理位置,这些进程间接地对该地区产生深刻影响。中华人民共和国成立后,中苏在戏剧艺术领域的合作快速发展,苏联剧院开始排演许多中国题材的剧目,两国剧团开始进行巡回演出。西伯利亚地区的中国工人通过业余演出形式将中国艺术传播给西伯利亚本地民众。20世纪50年代,双方艺术合作的中心城市是新西伯利亚和伊尔库茨克。20世纪60年代,双方的文化艺术交流中断,直到80年代中苏关系正常化之后双方在戏剧领域的交流与合作再次兴起。

气田水合物治理及节能降耗措施研究

在气田开采中,通过做好水合物治理以及配套的节能降耗工作,可以提升气田作业水平。从气田水合物概述展开论述,并分析了物理治理、化学治理、技术治理这三种气田水合物治理,然后从气田水合物治理中的伴热环节入手,提出了节能降耗的措施,实现了对气田水合物治理及节能降耗措施的研究,对提高油气田生产能源效率有着重要意义。

室内应急疏散的多人员Wi-Fi定位精度研究

应急疏散研究中的人员定位问题对于快速疏散人群和拯救被困人员具有重要的意义．为了确定Wi—Fi定位手段对于室内人员疏散的适用性，采用手持Wi—Fi设备和预设置的无线信号基准参考点，利用无线接收信号强度指数通过模式匹配的方式进行多人员定位的尝试．所得实验结果表明此方案的室内定位精度能达到5～7m．新方案所提供的定位精度能够区分室内多个体的移动路径，为相应疏散应用提供人员的动态位置信息描述．

板栗壳色素的提取技术及应用研究

板栗壳中含有天然色素成分,其安全性远高于合成色素,符合现代消费者对食品和化妆品安全性的要求。文章对板栗壳色素在食品、化妆品、纺织印染等行业的应用进行分析,旨在揭示其丰富色素资源的开发潜力。