Version based spatial record management techniques for spatial database management system

The search operation of spatial data was a principal operation in existent spatial database management system, but the update operation of spatial data such as tracking are occurring frequently in the spatial database management system recently. So, necessity of concurrency improvement among transactions is increasing. In general database management system, many techniques have been studied to solve concurrency problem of transaction. Among them, multi version algorithm does to minimize interference among transactions. However, to apply existent multi version algorithm to improve concurrency of transaction to spatial database management system, the waste of storage happens because it must store entire version for spatial record even if only aspatial data of spatial record is changed. This paper has proposed the record management techniques to manage separating aspatial data version and spatial data version to decrease waste of storage for record version and improve concurrency among transactions.

Visualization Techniques in Smart Grid

Visualization is an established methodology in scientific computing. It has been used in many fields because of its strong capability in large data management and information display. However, its applications in power systems, especially in Smart Grid are still in infancy stage. Besides, while there were a lot of researches working on visualizing data in transmission power system, the study on displaying distribution power system data was limited. Therefore, in this paper, author proposed some techniques to visualize the Smart Grid data at distribution. They are classified in three categories, which are low dimensional techniques, multivariate high dimensional techniques and Geographical Information System (GIS) techniques.

A subspace expanding technique for global zero finding of multi-degree-of-freedom nonlinear systems

A subspace expanding technique(SET) is proposed to efficiently discover and find all zeros of nonlinear functions in multi-degree-of-freedom(MDOF) engineering systems by discretizing the space into smaller subdomains, which are called cells. The covering set of the cells is identified by parallel calculations with the root bracketing method. The covering set can be found first in a low-dimensional subspace, and then gradually extended to higher dimensional spaces with the introduction of more equations and variables into the calculations. The results show that the proposed SET is highlyefficient for finding zeros in high-dimensional spaces. The subdivision technique of the cell mapping method is further used to refine the covering set, and the obtained numerical results of zeros are accurate. Three examples are further carried out to verify the applicability of the proposed method, and very good results are achieved. It is believed that the proposed method will significantly enhance the ability to study the stability, bifurcation,and optimization problems in complex MDOF nonlinear dynamic systems.

Spatial Analysis of the Aging Population and Socio-economic Factors of China:Global and Local Perspectives

Population aging has become an inevitable trend and exerted profound influences on socio-economic development in China.In this study,we utilized data from national population census and statistical yearbooks in 2010 and 2020 to explore spatio-temporal patterns of aging population and its coupling correlations with socio-economic factors from both global and local perspectives.The results from Local Indicators of Spatial Association(LISA)uncover notable spatial disparities in aging population rates,with higher rates concentrated in the eastern regions and lower rates in the western areas of the Chinese mainland.The results from the global correlation analysis with the changes in aging population rates show significant positive correlations with government interventions and industrial structures,but negatively correlated with economic development,social consumption,and medical facilities.From a local perspective,a Geographically Weighted(GW)correlation analysis is employed to uncover local correlations between aging trends and socio-economic factors.The insights gained from this technique not only underscore the complexity and diversity of economic implications stemming from population aging,but also provide invaluable guidance for crafting region-specific economic policies tailored to various stages of population aging.

Spatial Distribution Pattern and Application of Fourth-Generation Mature Larvae of Cotton Bollworm(Helicoverpa armigera Hübner) in Corn Field

[ Objective] The paper was to study the spatial distribution pattern of fourth-generation mature larvae of cotton bellworm in corn field. [ Method] The plots with different occurrence densities of fourth-generation cotton bollworm were investigated from August to September in 2009. Six groups of sampling data were obtained, and seven indicators including aggregation index method, Iwao method and Taylor method, etc. were used to determine its spatial distribution pattern. [ Result ] Aggregation index test showed that in all plots, Moore I 〈 0, Lloyed m＊/m 〈 1, Kuno Ca 〈 0, diffusion coefficient C 〈 1, diffusion index 16 〈 1, negative binomial distribution K 〈 0, indicating that mature larvae of cotton bollworm showed uniform distribution in summer corn. Iwae regression equation of fourth-genera- tion mature larvae of cotton boUworm in summer corn was m ＊ = 0. 090 6 ＋ 0. 766 9 m, r = 0. 986 3, indicating that the basic components of cotton bollworm distribu- ted was single individual, and mature larvae of cotton bollworm in summer corn showed uniform distribution. The optimal sampling number of fourth-generation ma- ture larvae of cotton bollworm in corn under different population densities could be calculated using formula N1 = （ 1. 090 6/m -0. 233 1 ）/D2. [ Conclusion] The result provided basis for accurate evaluation of population quantities and variation law of cotton boUworm, as well as prediction and control of the pest.

Temporal-spatial subspaces modern combination method for 2D-DOA estimation in MIMO radar

A 2D-direction of arrival estimation (DOAE) for multi input and multi-output (MIMO) radar using improved multiple temporal-spatial subspaces in estimating signal parameters via rotational invariance techniques method (TS-ESPRIT) is introduced. In order to realize the improved TS-ESPRIT, the proposed algorithm divides the planar array into multiple uniform sub-planar arrays with common reference point to get a unified phase shifts measurement point for all sub-arrays. The TS-ESPRIT is applied to each sub-array separately, and in the same time with the others to realize the parallelly temporal and spatial processing, so that it reduces the non-linearity effect of model and decreases the computational time. Then, the time difference of arrival (TDOA) technique is applied to combine the multiple sub-arrays in order to form the improved TS-ESPRIT. It is found that the proposed method achieves high accuracy at a low signal to noise ratio (SNR) with low computational complexity, leading to enhancement of the estimators performance.

Spatial Modulation-Based Ambient Backscatter: Bringing Energy Self-Sustainability to Massive Internet of Everything in 6G

Ambient backscatter communications(AmBC)is a new ultra-low-power communication paradigm,which holds great promise for enabling energy self-sustainability(ESS)to massive data-intensive Internet of Everything(IoE)devices in 6G.Recent advances improve throughput and reliability by adopting multiple-antenna techniques in conventional backscatter communications(CoBC),but they cannot be directly applied to AmBC devices for high spectral and energy efficiency due to the unknown RF source and minimalist design in backscatter tag.To fill this gap,we propose SM-backscatter,an AmBC-compatible system that greatly improves spectral efficiency while maintaining ultra-low-power consumption.Specifically,the SM-backscatter consists of two novel components:i)a multiple-antenna backscatter tag that adopts spatial modulation(SM),and ii)a joint detection algorithm that detects both backscatter and source signals.To this end,we theoretically obtain an optimal detector and propose two suboptimal detectors with low complexity.Subsequently,we derive the BERs of both the backscatter and source signals to analyze the communication performance by introducing a two-step algorithm.Our simulation results verify the correctness of the theoretical analysis and indicate that our system can significantly outperform existing solutions.

Empirical Analysis on Urbanization Patterns in Zhejiang Province Based on Spatial Economy and GIS

Regional core cities are the growth poles for regional economic development, thus the issue about efficient urbanization pattern has always become a hot spot among researchers and policy makers. The Spatial Economy can be employed to improve it. Nevertheless, there actually exists an obvious gap between its theoretical models and the empirical simulation. To do so, this paper modifies the measurement of initial geographical advantages Stelder gave, and implements the empirical analyses of urban distribution in Zhejiang during the period of 1980-1990 by means of computer simulations in GIS environment. There are several interesting results achieved in this process. Firstly, given the values of parameters （transport cost is r, substitution elasticity of manufacturing sector p, and income share of spending on manufacture δ）, initial geographical advantages have the different impacts on urban systems, namely, urban locations, numbers and sizes over time across space. Secondly, the cities were distributed without any overlay in geographical space, which makes the patterns of urbanization generate the largest possible economic efficiencies. Thirdly, the urban systems-the location, number and size of Cities-from the simulation of the study area are suitable for the actual social and economic situations in the real world during the testing periods. Such results may have substantial implications for the policy how to choose the way of urbanization in a region.

Spatial-temporal Evolution Analysis on Land Use Multifunctionality in the China-Vietnam Border Area

Exploring the spatial and temporal evolution characteristics of the border land use multifunctionality(LUMF)provides insights for taking advantage of border land use and optimizing border land use policies.Based on the improved Technique for Order Preference by Similarity to an Ideal Solution(TOPSIS)mode,this study identifies and evaluates the LUMFs in the China-Vietnam border area between 2000 and 2018 from the perspectives of agricultural production,social security,ecological service,landscape recreation,and national security.The results show that:1)The comprehensive land use functions in most counties and cities continued to be improved.2)The comprehensive land use function exhibits remarkable spatial divergence and aggregation characteristics.The high-value area of the agricultural production function and social security function evolves from the east to the west.In addition,the spatial evolution of ecological service function is complicated,without an obvious spatial divergence and aggregation pattern.The landscape recreation function shows different spatial differentiation characteristics in the early and middle stage,and forms a large cluster in the later stage.Finally,the spatial evolution pattern of the national security function is significant.3)Designing differentiated border land policies,improving border land use security,and establishing a long-term mechanism for ecological protection and ecological compensation can aid in optimizing the LUMF level in the border area.

面向空天地一体化网络的抗干扰技术研究

空天地一体化网络是实现全域通信和提供网络互联互通服务需求的重要基础设施之一。在未来的强对抗干扰环境中,确保其数据传输的有效性与可靠性对于维护国家安全具有重要意义。针对空天地一体化网络的对抗性的环境特点,探讨了在时频域和空域实现抗干扰的潜在应用与关键技术,并提出了对空天地一体化网络的综合思考。最后展望未来,以期为后续研究和实际应用提供方向性指导。

青海云杉一种重要害虫烟翅腮扁蜂越冬幼虫的空间分布型与抽样技术

为研究烟翅腮扁蜂(Cephalcia infumata)越冬幼虫在地下的空间分布,采用聚集度指标法、Taylor幂法则和Iwao回归法对烟翅腮扁蜂越冬幼虫的空间分布型进行分析。基于Iwao回归模型确定烟翅腮扁蜂越冬幼虫的理论数,通过序贯抽样技术得到不同允许误差(D=0.1、0.2、0.3)和经济阈值(m_0=3、5、10头/株)下的最大理论抽样数。结果表明,在宁夏罗山国家级自然保护区内,烟翅腮扁蜂1年发生1代,越冬幼虫主要分布在0~10 cm土壤中,在阳坡发生量大,呈聚集分布,符合负二项分布,种群聚集均数与种群平均密度呈线性关系,聚集程度随种群密度增大而增强。基于I_(wao)回归模型,在t=1.96时,当m_0=3头/株,D=0.1、0.2、0.3时,最大理论抽样数分别为596、149、66株;当m_0=5头/株,D=0.1、0.2、0.3时,最大理论抽样数分别为477、119、53株;当m_0=10头/株,D=0.1、0.2、0.3时,最大理论抽样数分别为388、97、43株。烟翅腮扁蜂的种群空间分布型为聚集分布,主要发生在林缘。基于序贯抽样确定的最大抽样数可用于指导烟翅腮扁蜂的监测和防治。

毕飞宇小说《哺乳期的女人》的空间叙事技巧

毕飞宇的获奖短篇小说《哺乳期的女人》一直被分析解构,却鲜有学者发现小说中的各种空间形态。文章首先从宏观构建地理空间承载人物活动,铺陈小说总体基调,继而从微观通过非地理空间的描述推动小说叙事进程,进一步阐述空间对人物命运走向的影响。从空间叙事的角度看,无论是地理空间还是非地理空间,都呈现出或对立、或矛盾、或变异的特性,并由此展现空间对人的规约以及人物的被动异化,最终揭示异化的根本原因。毕飞宇在《哺乳期的女人》中通过空间的叙事展现了其对于中国社会转型期村镇这一特定空间的总体看法。因此,对该小说中空间叙事的研究和对它们所呈意象的把握为探讨该小说的真正关怀指引方向,也更有助于发现毕飞宇小说的叙事技巧。

基于天地图的遵义红色旅游信息系统设计与实现

基于天地图的红色旅游服务系统,是空间信息技术与红色文化传播、旅游产业发展的一次深入融合,有利于直观地展现红色旅游信息资源,加强新时期爱国主义教育。本文以“天地图·遵义”建设为契机,充分结合遵义市红色文化特点,运用空间地理信息等现代科技手段建立遵义市红色旅游信息系统,将红军在遵义的重大革命事件、战斗遗址、行军路线,红色旅游等红色内容数字化、系统化,直观地展示中国共产党在遵义波澜壮阔的伟大征程,为社会公众了解遵义红色文化,为加强国民爱国主义教育提供素材。

南疆苹果园绣线菊蚜种群时空动态与调查抽样技术

绣线菊蚜Aphis spiraecola是新疆南疆地区苹果园的一种重要害虫,本文在阿克苏地区调查了绣线菊蚜在苹果园的种群消长动态,并分析其种群在果园的空间分布格局、理论抽样数及序贯抽样方法。结果表明,5月至8月苹果园中绣线菊蚜的种群动态曲线呈现出明显单峰,6月为种群发生的高峰期。在发生高峰期,绣线菊蚜在果园呈聚集型分布,种群密度在苹果树不同方位间没有显著差异。该时期苹果园绣线菊蚜的最适理论抽样模型为N=t^(2)/D^(2)(163.90/m+0.16),当防治阈值为1500头/12枝条时,序贯抽样模型公式为T_(n)=1500 n±1534√n。本研究结果为南疆苹果园绣线菊蚜种群调查与测报提供了重要科学依据。

李小食心虫在果园的空间分布变化及其最适抽样数的分析

【目的】研究李小食心虫(Grapholitha funebrana Treitscheke)幼虫在果园的空间分布,为李小食心虫的科学防控及确定最适抽样数提供理论依据。【方法】采用聚集指标法、Iwao回归分析、Taylor幂法则和Iwao最适抽样模型等方法,研究李小食心虫空间分布规律及确定其最佳抽样数。【结果】李小食心虫幼虫空间分布型与种群密度有关,在调查范围内(蛀果率在0.22%~10.10%),随着种群密度的增加其空间由均匀分布向聚集分布转变,蛀果率在0.22%时为均匀分布,蛀果率在1.67%~10.10%时为聚集分布,该变化是其生活习性和环境条件所引起的;确定了不同种群密度和允许误差下的最适抽样数。【结论】随着李小食心虫幼虫种群密度的增加其空间分布亦由均匀分布向聚集分布转变;对于李小食心虫聚集分布的果园(蛀果率>1.67%的果园),应重点防治为害严重株或部位,有效控制该虫的扩散。

形状记忆环氧材料漏电流抑制技术及耐辐照性能提升方法

针对航天器空间可展开结构用形状记忆聚合物材料在空间辐照环境中电荷输运性能发生变化时易产生漏电流,从而造成结构器件劣化、击穿,甚至影响航天器正常运行的问题,从高分子三维网状结构设计角度出发,提出一种形状记忆聚合物辐照感应漏电流抑制方法,实现了形状记忆聚合物的性能提升,能够指导空间可展开结构材料的选型和设计。基于常用的双酚A环氧树脂材料,通过引入不同官能度和配比的固化剂调控其高分子三维网状结构,获得了具有不同热力学性能的形状记忆环氧材料。采用X射线辐照感应电导率在线测试系统,表征不同体系环氧材料在不同辐照功率下的漏电流演变情况。研究结果表明:相较于固化剂官能度为5的形状记忆环氧材料体系,固化剂官能度为6环氧材料体系的X射线辐照感应电导率随固化剂配比变化的幅度减小了约50%,即选择官能度相对较高的固化剂体系环氧材料,能够构建更加致密的高分子三维网状结构,可获得更加稳定的热力学和X射线辐照感应电导性能,更有利于抑制辐照感应漏电流,从而增强了空间展开结构X射线辐照防护效果。

基于差异冻结技术的深厚冲积层三维冻结温度场数值计算分析

为了探究人工地层冻结(artificial ground freezing, AGF)多圈管冻结壁温度场分布与发展规律,以淮北青东煤矿东风井为工程背景,利用现场实测数据和COMSOL Multiphysics软件建立三维冻结温度场数值计算模型,分析了立井井筒所在土层在差异冻结技术下的冻结温度场时空演化规律。研究结果表明:在对比分析中三圈管相较两圈管冻结扩展速度较快,相同的冻结时间下,冻结壁平均温度要低0.73~3.32℃·d^(-1),有效厚度增加0.38 m;砂土层相同冻结时间的条件下冻结壁平均温度要比黏土层低0.94~1.50℃,有效厚度增加0.21 m。冻结井筒计算范围内,径向温度场呈现出圈管之间温度低,圈管两侧温度较高的“马鞍型”分布;在土体深度方向,不同土性的土层温度梯度较为明显,具体表现为三圈管以及细砂层位温度更低,30 d左右Ⅱ层土体(三圈管砂土层)降温速率达到最大,约为1.12℃·d^(-1),首先完成土体降温阶段进入冻结壁交圈和拓展阶段,此时其他土层仍处于土体降温阶段。“长短腿”冻结管布置形式既可以提高井筒开挖的时间,缩短工期;又可以防止深部冻土入荒径过多,降低开挖难度,节约工程成本。采用差异冻结的方式,开机冻结30 d,去路盐水温度降至-30℃后维持该温度循环制冷盐水,使得该冻结工程取得了圆满成功。此研究可以为类似矿井冻结施工提供一定的参考。

Coherent optical adaptive technique improves the spatial resolution of STED microscopy in thick samples

Stimulated emission depletion(STED) microscopy is one of far-field optical microscopy techniques that can provide sub-diffraction spatial resolution. The spatial resolution of the STED microscopy is determined by the specially engineered beam profile of the depletion beam and its power. However, the beam profile of the depletion beam may be distorted due to aberrations of optical systems and inhomogeneity of a specimen's optical properties, resulting in a compromised spatial resolution. The situation gets deteriorated when thick samples are imaged. In the worst case, the severe distortion of the depletion beam profile may cause complete loss of the superresolution effect no matter how much depletion power is applied to specimens. Previously several adaptive optics approaches have been explored to compensate aberrations of systems and specimens. However, it is difficult to correct the complicated high-order optical aberrations of specimens. In this report, we demonstrate that the complicated distorted wavefront from a thick phantom sample can be measured by using the coherent optical adaptive technique. The full correction can effectively maintain and improve spatial resolution in imaging thick samples.

苹果蠹蛾在苹果树上的空间分布型及抽样技术研究

为明确苹果蠹蛾成虫在新疆南疆小海子垦区苹果树上的空间分布型和理论抽样技术,采用聚集度指标、Iwao回归分析法和Taylor幂法则分析了苹果蠹蛾成虫的空间分布型,应用Iwao理论抽样和序贯抽样技术,建立最适南疆第三师小海子垦区苹果蠹蛾成虫田间调查的抽样模型和抽样数。结果表明:苹果蠹蛾成虫在田间的空间分布型受密度的影响较大,成虫在每诱捕器平均诱虫量(m)>5时呈聚集分布,个体间相互吸引,分布的基本成分为个体群,密度越大,个体群聚集度越高,聚集原因是由自身的习性和环境因素综合作用引起的;在每诱捕器平均诱虫量(m)≤5时,个体间相互排斥,呈均匀分布。进一步分析提出了不同种群密度下苹果蠹蛾成虫的理论抽样模型和基于防治指标的序贯抽样技术,可为科学开展田间苹果蠹蛾虫口调查和防治工作提供技术支撑。

质谱成像技术在过敏性疾病中的应用进展

近年来,质谱成像技术取得了巨大进步,其在过敏性疾病中的应用取得了一定进展。质谱成像技术可用于分析食物、接触物等导致过敏性疾病的分子分布信息,获取过敏原中的特征性分子。此外,质谱成像技术还被用于研究过敏原及其代谢物等小分子物质在过敏性疾病中的空间分布特征。本文就质谱成像技术在临床蛋白质组学、IgE抗体和肥大细胞、食物过敏、特应性皮炎、过敏性哮喘等研究中的应用现状进行综述。