基于无线局域网接收信号强度分析的混合室内定位方法

为了给用户提供丰富的室内位置服务,需要在结构复杂且人员密集的室内环境中进行精确定位。根据对无线局域网接收信号强度的分析,可以利用三角定位算法和指纹定位算法进行混合室内定位。首先在网格划分的基础上离线构造参考点接收信号强度数据库,并采用三角定位算法估算所有无线接入点的位置,然后根据定位精度需求设定混合定位方法的接收信号强度阈值。在线定位时,根据用户终端实际接收到的无线接入点个数和信号强度选择三角定位算法或指纹定位算法进行位置计算。实验表明,该室内定位方法有效且稳定。     

基于众包校正的多源融合室内定位算法

为了提高室内定位算法的精度，本文融合Wi-Fi和蓝牙两种信号源，提出了一种结合粗定位和众包校正的适用于多用户环境的室内定位算法。该定位算法分为离线和在线两个阶段，离线阶段的主要任务是构建多个指纹库，在线阶段的主要任务是进行粗定位和众包校正。粗定位分别利用Wi-Fi接收信号强度指示和蓝牙接收信号强度指示计算用户的粗略位置和用户间的距离；众包校正包括聚类校正和虚拟空间校正两个部分，它利用用户间的距离和用户组的位置分布提高定位精度。在UJIIndoorLoc和IPIN2017-CAR数据集上进行验证，实验结果表明，提出的定位算法将平均定位误差分别降至4.96 m和4.35 m。     

RFID技术在移动机器人同步定位中的应用

提出了一种用于室内移动机器人的同步定位算法.该算法利用射频识别(RFID)系统,将RFID标签实现的无线传感器网络与SLAM算法结合,依据RFID阅读器获得的标签数据对机器人定位.实验证明:基于RFID系统的定位算法在2维环境中能有效地对机器人进行定位和跟踪.     

基于LS-SVM方向判别模型的WLAN室内定位方法

为解决WLAN室内定位中信号在传播过程受人体遮挡产生阴影衰落而影响定位精度的问题,提出了一种最小二乘法支持向量机(LS-SVM)方向判别模型的WLAN室内定位方法。该方法主要分为两个部分:首先,充分利用人体在不同遮挡方向上产生阴影衰落的接收信号强度变化(RSS)特征信息,判定人体遮挡方向;然后,通过LS-SVM回归算法建立指纹点特征数据与位置之间的映射关系获取定位点位置结果。实验结果表明,与传统利用SVM的定位方法相比,提出的方向判别模型可解决人体遮挡产生的阴影衰落影响定位精度的问题,提高了定位的实用性和鲁棒性。     

改进K-means聚类的自适应加权K近邻指纹定位算法

针对指纹定位精度易受指纹数据K-means聚类预处理效果不佳、加权K近邻算法采用固定K值进行匹配定位精度差等问题,提出一种基于改进K-means聚类的自适应加权K近邻算法.算法在对指纹数据进行聚类计算过程中充分考虑参考点间接收信号强度值与实际物理坐标的双重影响,以避免参考点分类不明确;根据每个测试点的匹配参考点之间实际距离的均值和标准差设置阈值,动态选择K值.实验结果证明,改进K-means聚类的自适应加权K近邻算法相较于传统室内定位算法定位精度提高了44％,可为相关应用提供更精确的定位服务.     

一种改进型几何聚类指纹室内定位方法

为解决传统加权K最近邻算法(WKNN,Weighting K-Nearest Neighbor)定位方法中选取K值存在局限性影响定位精度的问题,提出了一种改进型几何聚类指纹室内定位方法。该方法首先利用网格分布在定位区域构建指纹点几何位置分布,采集指纹点接收信号强度(RSS,Received Signal Strength)和位置信息,建立指纹定位数据库;然后,利用支持向量机分类算法在解决高维度和非线性问题上的优势选取定位点的多个近邻指纹点,根据对定位贡献度的大小筛选近邻指纹点并构建几何聚类定位区域;最后利用WKNN算法进行定位。实验结果表明,提出的方法解决了传统WKNN方法中多边形定位区域在K值选取存在局限性的问题,具有更高的定位精度和工程实用性。     

基于WiFi指纹的高精度室内定位融合算法

针对室内环境中指纹定位接收信号强度信息的高维时变特性以及动态目标定位误差的累积问题,提出了一种基于梯度提升决策树与粒子滤波相结合的融合算法。该算法首先利用梯度提升决策树算法建立的位置坐标与接收信号强度之间的非线性映射模型,对在线接收的信号强度数据进行特征分类判别,实现位置的初步估计;随着目标的运动,进一步结合粒子滤波方法,迭代地实现动态目标位置的精确预测;另外,将定位轨迹与实际轨迹进行对比,以验证该算法的稳定性。实验仿真结果表明:累积分布函数在80%的百分位处,提出算法的定位精度控制在1.19 m以内,明显优于基于支持向量机、随机森林等定位算法;同时较基于梯度提升决策树算法的定位精度提升了34.9%;所获得的定位轨迹与实际轨迹的趋势一致且趋于收敛。     

基于群智感知和非监督式学习的室内定位指纹库构建算法

针对指纹法定位中的指纹库构建耗费大量人力和时间的问题,提出了一种基于群智感知和非监督式学习的室内定位指纹库构建算法.首先利用群智感知的方式采集无线接入点的接收信号强度获取原始指纹数据集.然后针对原始指纹数据的冗余杂乱和指纹注释问题,提出基于学习向量量化(LVQ)和多维标度(MDS)结合的一种新颖算法FLM来解决.最终有效构建室内定位指纹库.最后基于射线跟踪模型(ray-tracing)建立仿真实验场景,仿真结果表明其指纹库建立效率得到显著提高,应用于基本定位算法的定位误差80%,在2.6,m以下,而且单次定位的计算量下降63%,.     

基于多径指纹的概率匹配室内定位方法

空间交替广义期望最大化(SAGE)算法可以高效地实现室内信道多径参数的估计,同时提供相对较高的精度。该文提出一种基于多径指纹的概率匹配室内定位方法,将SAGE算法得到的信道多径参数作为指纹数据进行定位,以求获得更好的定位精度和鲁棒性。通过分析典型场景下的定位实验测量结果,并与同类型的传统室内定位方法进行比较,验证了该方法的有效性。     

一种基于KNN的室内位置指纹定位算法

提出了一种基于KNN 的FM、DTMB 联合信号位置指纹匹配算法,并根据不同位置具有不同信号强度将匹配过程设计为一个多分类算法模型. 离线阶段,通过采集FM 信号与DTMB 信号的强度信息,完成位置指纹库的构建. 在线匹配阶段,利用KNN 算法对新采集到的数据进行加权欧氏距离匹配,通过对K 值以及特征向 量的选取对定位误差进行了分析. 仿真结果表明,该算法在室内定位中具有良好的鲁棒性和准确度,90% 概率下定位精度2.3 m.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-