The Temporal and Spatial Evolution Characteristics Analysis of Jiangsu Tourism Economy

[Objective] The paper aimed to reflect the spatial pattern and temporal and spatial evolution characteristics, the differences between inter-regional tourism economy was measured from the quality aspect, which provided a reference for the local governments in the future tourism development. [Method] Using the location entropy methods, three time periods side of tourism-related date of 2000, 2005, 2007 were selected, from the angle of the spatial pattern and the evolution of the differences within the different scales, the spatial and temporal evolution characteristics of the economic development level of Jiangsu were analysed. [Result] The results showed that from the aspect of spatial evolution pattern, as time goes on, the economic development of Jiangsu tourism has experienced morphological evolution of concentration- dispersion decrease-stability; when it comes to the development of the tourism economy, in recent years, the overall gap between the tourism economy in Jiangsu did not widen, the gap mainly led by the region one after another. According to their volatility, it will be divided into four categories: A Stable type (Wuxi, Xuzhou, Lianyungang and Taizhou), B Increasing type (Huai’an), C Fluctuations type (Nanjing, Changzhou, Suzhou and Yangzhou) and D Depression type (Nantong, Yancheng, Zhenjiang and Suqian). [Conclusion] Location entropy was quoted into tourism economic analysis, the method was simple and easy to understand, the result was accurate and convincing, which provided a reference for travel economic development and investment decision-making of Jiangsu.

Effects of Unbalance Location on Dynamic Characteristics of High-speed Gasoline Engine Turbocharger with Floating Ring Bearings

For the high-speed gasoline engine turbocharger rotor, due to the heterogeneity of multiple parts material, manufacturing and assembly errors, running wear in impeller and uneven carbon of turbine, the random unbalance usually can be developed which will induce excessive rotor vibration, and even lead to nonlinear vibration accidents. However, the investigation of unbalance location on the nonlinear high-speed turbocharger rotordynamic characteristics is less. In order to discuss the rotor unbalance location effects of turbocharger with nonlinear floating ring bearings（FRBs）, the realistic turbocharger of gasoline engine is taken as a research object. The rotordynamic equations of motion under the condition of unbalance are derived by applied unbalance force and nonlinear oil film force of FRBs. The FE model of turbocharger rotor-bearing system is modeled which includes the unbalance excitation and nonlinear FRBs. Under the conditions of four different applied locations of unbalance, the nonlinear transient analyses are performed based on the rotor FEM. The differences of dynamic behavior are obvious to the turbocharger rotor systems for four conditions, and the bifurcation phenomena are different. From the results of waterfall and transient response analysis, the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different from the different unbalance locations, and the non-synchronous vibration does not occur in the turbocharger and the amplitude is relative stable and minimum under the condition 4. The turbocharger vibration and non-synchronous components could be reduced or suppressed by controlling the applied location of unbalance, which is helpful for the dynamic design, fault diagnosis and vibration control of the high-speed gasoline engine turbochargers.

Prognostic impact and reasons for variability by tumor location in gastric cancer

BACKGROUND Gastric cancer(GC)is a highly prevalent gastrointestinal tract tumor.Several trials have demonstrated that the location of GC can affect patient prognosis.However,the factors determining tumor location remain unclear.AIM To investigate the tumor location of patients,we went on to study the influencing factors that lead to changes in the location of GC.METHODS A retrospective evaluation was carried out on 3287 patients who underwent gastrectomy for GC in Zhejiang Cancer Hospital.The patients were followed up post-diagnosis and post-gastrectomy.The clinicopathological variables and overall survival of the patients were recorded.By analyzing the location of GC,the tumor location was divided into four categories:“Upper”,“middle”,“lower”,and“total”.Statistical software was utilized to analyze the relationship of each variable with the location of GC.RESULTS A total of 3287 patients were included in this study.The clinicopathological indices of gender,age,serum levels of carcinoembryonic antigen(CEA),carbohydrate antigen(CA19-9)and CA72-4 levels,were significantly associated with tumor location in patients with GC.In addition,there was a strong correlation between GC location and the prognosis of postoperative patients.Specifically,patients with“lower”and“middle”GC demonstrated a better prognosis than those with tumors in other categories.CONCLUSION The five clinicopathological indices of gender,age,CEA,CA19-9 and CA72-4 levels exhibit varying degrees of influence on the tumor location.The tumor location correlates with patient prognosis following surgery.

Characteristics of histological location of bursin in sacculus rotundus and gut-associated lymphoid tissues of rabbits

The distribution of bursin in sacculus rotundus and gut-associated lymphoid tissues was investigated in rabbit by immuno-histochemical staining method with anti-bursin monoclonal antibody （McAb）2F9-4. The results indicated that the appearance of the bursin-containing cells coincided with the morphodifferentiation and growth process in rabbit. Bursin immunized cells not only distributed in dome epithelium and mucosal epithelium, but also in follicular germinal center, dome, T-cell area, goblet cell, inter-epithelial lymphocyte and cap-zone of sacculus rotundus. This founding suggested that bursincontaining cells in sacculus rotundus might play an important role in intestinal mucosal immunity.

Development of Wages and Salaries of Czech Employees During the Last Period by Educational Attainment and Forecasts for 2011 and 2012

This paper deals with the development of sample characteristics of wage distribution in recent years in the Czech Republic by the highest educational attainment. Gross monthly wage is the variable investigated. We distinguish the following scale of the highest educational attainment： primary and incomplete education, secondary education without GCSE, secondary education with GCSE, higher vocational and bachelor education and tertiary education. Forecasts of wage distribution have been developed for the next two years for all of these categories. Three-parametric lognormal curve formed the basis of the theoretical probability distribution. Parameter values of relevant three-parametric lognormal curves were then estimated using the method of L-moments of parameter estimation. Forecasts of sample values of L-moments were calculated using trend analysis of their past development and the parameters of three-parametric Iognormal curves for forecasts of wage distribution were calculated using the predicted values of the first three sample L-moments. We have obtained the forecasts of wage distribution by the highest educational attainment on the basis of these probability density functions.

Research on Leak Location of Liquid-filled Pipe Based on Frequency Dispersion Characteristics

Due to the material problems and force majeure factors,the leakage will be occurred on the liquid-filled pipe resulting in waste of resources,environmental pollution and even endangering safety.Acoustic wave detection technology is widely used in buried pipeline leak detection,this technology mainly uses the wave(n=0,s=1)in the pipeline acoustic wave to locate the leak.When the leakage acoustic signal propagates along the liquid-filled pipe,the frequency dispersion characteristics can be obtained by wavelet decomposition.And there is a time delay(time difference)value between the leaky acoustic signals collected by the sensors at both ends of the leak.The outputs show that the results obtained by wavelet decomposition are in good agreement with the theoretical calculation results.Based on the obtained dispersion relation,the time delay values at different characteristic frequencies are analyzed by the cross-correlation method,and the leak location accuracy is discussed.This research content provides theoretical support and engineering application guidance for pipe leakage location technology.

Experimental studies on pillar failure characteristics based on acoustic emission location technique

Acoustic emission （AE） technique is a useful tool for investigating rock damage mechanism, and is used to study the temporal-spatial evolution process of microcracks during the similar pillar material experiment. A combined AE location algorithm was developed based on the Least square algorithm and Geiger location algorithm. The pencil break test results show that the location precision can meet the demand of microcrack monitoring. The 3D location of AE events can directly reflect the process of initiation, propagation and evolutionary of microcracks. During the loading process, stress is much likely concentrated on the area between pillar and roof of the specimen, where belongs to danger zone of macroscopic failure. When rock reaches its plastic deformation stage, AE events begin to decrease, which indicates that AE quiet period can be seen as precursor characteristic of rock failure.

架空配电线路故障电弧的电磁辐射特性及故障定位应用

针对架空配电线路电弧接地故障点定位难题,该文研究架空配电线路故障电弧的电磁辐射特性,探索基于电磁辐射信号的电弧故障定位方法的可行性。通过10 k V配网真型故障模拟试验平台,分析接地电弧电磁辐射的时域与频域特性及传播衰减规律,结果表明:电弧电流的电磁辐射特征频段为20~30 MHz,该特征频段不会受到中性点接地方式、电弧接地介质与线路结构参数的显著影响,且特征频段内辐射信号在传播过程中衰减较慢。在此基础上,设计一种小型化三角形单极子–环形组合平面天线,工作频率为20~500 MHz。利用自制天线开展小型电弧故障定位实验,为后续配网电弧故障定位的应用研究提供基础。

人工智能赋能城市滨水空间秋季景观特征识别与活力提升——以上海市黄浦江为例

上海市积极深化“一江一河”建设,打造具有全球影响力的世界级滨水空间,以绿化品质提升的“四化”建设为引领,促进季节性景观营造,从而激发滨水空间活力。针对城市滨水空间尺度大、范围广、数据多的特征,以人工智能赋能下滨水秋季景观特征的全覆盖、多时相、数字化识别为核心,以上海市黄浦江滨水空间中心城区段为例,训练滨水空间秋季景观特征识别的深度学习算法构建语义分割模型,实现对实证案例大批量样本数据的秋季景观特征智能化识别与测度;通过基于位置的服务(location-basedservices,LBS)大数据分析手段,量化揭示上海市黄浦江滨水空间中心城区段活力时空分布特征。探索影响城市滨水空间活力的秋季景观特征的关键因素,为城市滨水空间秋季景观的营造与活力激发提供理论依据与技术支撑。

深圳市土地出让区位选择空间特征及影响因素研究

以深圳市2007—2022年的2908宗土地出让地块为样本,采用GIS空间分析、数据统计分析等方法对深圳土地出让区位选择空间特征与影响因素进行了研究.研究结果表明:(1)土地出让数量最多的是龙岗及宝安区,土地出让收入最高的是南山及宝安区,最少的都是盐田区,土地出让数量和收入总体上都呈稳中有升的趋势.(2)深圳商服、住宅、工矿仓储和总用地的出让均呈显著集聚模式.(3)总用地出让热点区分布较均衡,冷点区在东南部较多.商服用地热点区高度集聚于西南部的都市核心区.住宅用地热点区分布相对均衡,且在深圳中部的热度明显超过另两类用地.工矿仓储用地热点区集聚于北部边缘地区.(4)总用地出让的核密度在西南部及东北部高,东南部低,呈多中心多层次点状集聚的空间特征.商服用地高密度区集聚于西南部,呈大规模连片分布单中心集聚的空间特征.住宅用地高密度区分布较均衡,呈多中心多层次点状集聚的空间特征.工矿仓储用地高密度区主要位于北部,且临近深莞、深惠交界处,呈多中心点状集聚的空间特征.(5)土地出让区位选择模式是商服用地高度集聚于前海等城市新中心,工矿仓储用地主要位于北部城市边缘地区,住宅用地夹于另两类用地之间的同时也与商服、工矿仓储用地混合分布.(6)土地出让区位选择受到交通、地形、经济与人口规模、城市化和土地利用与城市规划等多方面的综合影响.

轨道交通产业集群识别及时空演变特征分析

本文应用区位熵识别我国轨道交通产业集群状态,进而构建Logistic曲线模型和空间演化模型分析轨道交通产业集群时空演化特征。研究结果表明:(1)我国轨道交通产业集群总体呈递增趋势,到2020年已基本形成,但地区间集群水平存在差异。(2)时间上,轨道交通产业集群发展的三个关键点分别为2010年、2017年与2023年,呈现阶段性发展特征;(3)空间上,轨道交通产业集群全局空间自相关性渐进增强,呈现“集聚”发展模式,同时产业集群空间重心在116.0419°E~115.5198°E,34.6150°N~32.9530°N之间变动,即椭圆重心由东北向西南移动,空间椭圆逐渐向正圆趋近,在空间分布上趋向均衡发展,同时产业集群的空间整体分布方向呈现从偏东北西南向正北正南偏移的趋势。基于此,我国应整合产业资源,加强轨道交通产业集群效应,稳步推进集群转型发展,进一步优化空间布局。

适用于声源定位的气体绝缘输电线路超声导波传播特性研究

基于到达时间差(TDOA)的声源定位方法是当前气体绝缘输电线路(GIL)故障定位的主要方式,声波在GIL结构上的传输特性深刻影响着定位结果的准确性。为进一步提升故障定位精度,该文提出了考虑导波频散与多模态特性的GIL壳体声传输分析模型,以典型220 kV GIL管段为研究对象,建立声波传输有限元模型,研究了导波特性对故障定位的影响,确定了适用于故障定位的超声导波模态以及GIL非直管结构对该模态导波的衰减与时延量,通过现场定位试验验证了分析模型的可行性,为GIL声源故障定位系统的传感器配置与定位阈值设置提供了计算依据。结果表明,在20~60 kHz频带内,F(1,1)模态导波具有能量高、波形形状稳定、抗干扰能力强等特点,使用该模态导波进行故障定位精度较高。GIL非直管结构会对F(1,1)模态导波造成较大的幅值衰减与一定程度的时延,在故障定位中考虑非直管结构衰减与时延影响可以使定位误差降低60%以上。

基于PT-PFM激励阻抗谱数字重构的电缆故障诊断定位

由于传统频谱测试仪器增益带宽积有限,高频区间内输出电压过低,在针对长距离电缆测试时信号衰减较为严重,导致阻抗谱在高频区间内存在一定失真问题。该文提出一种基于伪梯形波激励阻抗谱数字重构算法的电缆故障诊断定位算法。分析不同故障类型下电力电缆的局部故障阻抗对电缆输入阻抗谱的影响规律、首端激励电压信号的衰减特性和不同电压幅值的功率传输特性。设计一种基于Si C高速逆变器的大容量伪梯形励磁系统,用于测量最高频率7 MHz的阻抗谱信息,利用阻抗谱数字重构方法实现0.1 Hz~60 MHz宽频区间的全覆盖。与传统的低压正弦激励相比,采用该时空转换函数的定位结果具有更小的区间振荡和更快的收敛速度。缺陷定位精度提高了80%,验证了该方法的有效性和准确性。

基于改进灰狼优化算法的结构损伤识别

结合模态柔度矩阵、广义模态柔度矩阵和振型三个识别精度较好的指标,构造新的目标函数求解损伤识别问题。通过Nelson方法求解得到的频率与振型的导数,得到对结构刚度发生变化时更具敏感性的位置,然后在这些位置布置传感器以提取结构信息。针对原有的灰狼算法虽然全局搜索能力强,但是存在局部搜索精度差的问题,本文从初始种群和收敛因子等方面着手,改善灰狼算法的局部搜索能力及收敛速度。最后利用提出的方法,通过识别梁模型及桁架模型中的损伤单元说明本文方法的有效性。

桂林市区游客酒店住宿的区位特征与形成机制——基于旅游流轨迹的实证分析

酒店等住宿设施是体现旅游城市形象和服务水平的重要窗口,对其空间分布特征的现有实证研究中,鲜有基于游客需求侧维度的系统解读,亟需一个能对多元结论提供合理解释的分析框架,以明晰不同结论的场景约束条件和应用价值边界。以携程旅行网上发布的桂林游记作为数据来源,提取游客旅游轨迹中的住宿信息,运用聚类分析、核密度估计、空间句法等方法解读桂林市区游客酒店住宿的空间特征,并从“旅游地—旅游流—酒店”三元关系的视角解读游客住宿空间分布的形成机制。结果表明:①桂林市区游客住宿空间具有显著的集聚特征,表现为多节点的分布格局;②酒店等住宿设施的集聚节点可分为“邻近交通门户”“邻近目标景观”“位于交通便捷区”三大类型,表现为至少具有“便捷旅游交通”与“邻近景观资源”两大空间特征之一;③酒店等住宿设施的集聚受旅游流空间集散的影响,而旅游流空间集散受旅游地空间结构的影响,“旅游地—旅游流—酒店”间的关联脉络构成游客住宿空间分布机制的解析框架;④“旅游地—旅游流—酒店”的分析脉络可以将传统研究中因侧重不同视角而得出的多元结论纳入同一框架并给出理论解释。

在线社交网络中用户地理位置预测综述

随着智能移动终端的日益普及,人们越来越多地利用社交网络平台(如Twitter、新浪微博等)获取信息、评论和交流.虽然全球卫星定位系统(GPS)设备能够精确获取位置信息,但是大量用户出于隐私和安全的考虑不会直接共享自己的位置信息.因此,如何获取在线用户的地理位置成为了一个前沿的研究领域以及学术界和工业界共同关注的重要课题,并且成为众多下游应用的基础,例如基于位置的定向广告投放、事件/地点的推荐、自然灾害或疾病预警和网络犯罪的追踪等.详细总结了预测社交网络用户地理位置的方法、数据、评价体系和基础算法.首先,归纳了不同的定位任务以及相应的评价指标;其次,针对不同的任务梳理所用的数据类型和数据融合方式,并且,详尽分析了已有的信息抽取和特征选择方式及其优缺点;再次,对现有定位模型和算法进行分类,从地名词典、传统机器学习和深度学习3个方面对用户定位方法进行阐述和分析;最后,总结了社交网络用户地理位置预测的难点和面临的挑战,并展望该领域的发展趋势和未来研究所需要关注的方向.

基于参数特征映射的多站时差测量实现

在现代定位系统中,传统的时差测量方法往往受限于信号调制方式、噪声干扰以及硬件实现复杂度等因素,难以保持高精度和实时性。针对上述问题,本文设计一种基于参数特征映射的多站时差定位系统中时差测量方法,由主站检测并产生参考信号,广播至各从站;各站根据此参考信号基于频域互相关算法完成时差测量。该方法有效提高二进制相移键控(binary phase shift keying,BPSK)信号、四相相移键控(quadrature phase shift keying,QPSK)信号、频移-相移复合调制(frequency shift keying-phase shift keying,FSK-PSK)信号等时差测量精度。本文给出了基于现场可编程逻辑门阵列(field programmable gate array,FPGA)时差测量方法的硬件实现,采用实时动态压缩方法,FPGA算法实现资源减少50%;采用抛物线拟合方法,提高时差估计精度;采用基于参数特征映射的数据传输方法,保障多站数据的完备、避免数据缺失和冗余的同时,数据传输量降低95%。仿真与试验测试结果表明,信噪比(signal-to-noise ratio,SNR)大于等于5 dB时,PSK调制信号时差测量精度优于5 ns;对于前沿缓变调制信号,随着脉冲上升沿宽度增大,时差测量精度无明显变化;最后,在外场试验与飞行试验结果中验证方法的有效性与可行性,为高精度多站时差定位系统的实际应用提供了有力支持。

基于多端行波频率矩阵的复杂配电网故障定位方法

针对配电网线路参数受依频变化影响导致现有故障定位方法实现复杂以及行波传输速度无法准确计算的问题,基于多端行波频率矩阵,提出一种不依赖波头时间信息的复杂配电网故障定位方法。通过对故障行波固有频率主成分与传输距离的关系进行分析,定义各分支节点的参考端,并计算真实故障发生前的基准固有频率矩阵与真实故障发生后的故障固有频率矩阵之间的差值,最终得到相应的故障分支判定原理。在判定故障分支的基础上,按照故障点到参考端的路径不经过分支节点或经过分支节点数量最少为原则选取参考端,同时计算对应参考端故障固有频率主成分下的波速度,进而对故障点位置实现精确定位。仿真结果表明,所提方法无须检测行波波头时间,通过构建多端频率矩阵准确刻画配电网拓扑任一分支发生故障的情形,在保证故障分支可靠判定的同时实现了频率分量与波速度相互匹配,大大提高了故障定位精度,且定位结果不受故障位置、类型、过渡电阻、初相角影响。

百年简牍研究主题流变考:基于地域维度

基于百年以来出土的简牍文献,研究者已展开了大量研究。以简牍文献出土的地域为切入点,深入比较分析不同研究者对于简牍研究的主题特征,就会发现,不同地域出土的简牍文献特征存在着一定的差别,从而使研究形成了各具特色的主题。由于不同地域出土的简牍文献的研究侧重点存在着明显差异,由此构成了一个特征鲜明的简牍研究地域与主题分布的画卷。这一发现可望为简牍学在学科体系、学术体系与话语体系建设中,将不同地域特征纳入其中提供参照。

CEO社会阶层影响了跨国公司OFDI政治风险区位选择吗?——基于中国跨国公司微观数据

针对对外直接投资(outward foreign direct investment,OFDI)区位选择呈现出向高政治风险地区发展的新态势,不同于以宏观国家层面、中观行业层面、微观企业层面为视角的已有研究,本研究以更为微观的企业内部高层决策者特征——CEO社会阶层为视角,选择沪深2009?2017年中国跨国公司OFDI事件为研究样本,基于高阶理论和印记理论,使用Logit回归方法,探索CEO社会阶层对跨国公司OFDI政治风险区位选择的影响机制与边界条件。研究结果发现,CEO社会阶层与跨国公司OFDI政治风险区位选择之间存在显著的正U型关系,即社会阶层越高/低的跨国公司CEO倾向于做出向OFDI高政治风险区位选择的战略决策,中间社会阶层的跨国公司CEO倾向于做出向OFDI低政治风险区位选择的战略决策;CEO政治资本对CEO社会阶层与跨国公司OFDI政治风险区位选择之间正U型关系的正向调节作用不显著。本研究为拓展OFDI政治风险区位选择影响因素的研究范畴做出贡献,为中国跨国公司从公司治理结构角度加强高管集体审慎决策,充分发挥CEO社会阶层优势或有效抑制CEO个人有限理性决策不足,进而做出OFDI政治风险区位选择科学决策提供理论支撑和管理启示。