Passive IoT Localization Technology Based on SD-PDOA in NLOS and Multi-Path Environments

Addressing the challenges of passive Radio Frequency Identification(RFID)indoor localization technology in Non-Line-of-Sight(NLoS)and multipath environments,this paper presents an innovative approach by introducing a combined technology integrating an improved Kalman Filter with Space Domain Phase Difference of Arrival(SD-PDOA)and Received Signal Strength Indicator(RSSI).This methodology utilizes the distinct channel characteristics in multipath and NLoS contexts to effectively filter out interference and accurately extract localization information,thereby facilitating high precision and stability in passive RFID localization.The efficacy of this approach is demonstrated through detailed simulations and empirical tests conducted on a custom-built experimental platform consisting of passive RFID tags and an R420 reader.The findings are significant:in NLoS conditions,the four-antenna localization system achieved a notable localization accuracy of 0.25 m at a distance of 5 m.In complex multipath environments,this system achieved a localization accuracy of approximately 0.5 m at a distance of 5 m.When compared to conventional passive localization methods,our proposed solution exhibits a substantial improvement in indoor localization accuracy under NLoS and multipath conditions.This research provides a robust and effective technical solution for high-precision passive indoor localization in the Internet of Things(IoT)system,marking a significant advancement in the field.

Fracture evolution and localization effect of damage in rock based on wave velocity imaging technology

By utilizing wave velocity imaging technology,the uniaxial multi-stage loading test was conducted on siltstone to attain wave velocity imagings during rock fracture.Based on the time series parameters of acoustic emissions(AE),joint response characteristics of the velocity field and AE during rock fracture were analyzed.Moreover,the localization effect of damage during rock fracture was explored by applying wave velocity imagings.The experimental result showed that the wave velocity imagings enable three-dimensional(3-D)visualization of the extent and spatial position of damage to the rock.A damaged zone has a low wave velocity and a zone where the low wave velocity is concentrated tends to correspond to a severely damaged zone.AE parameters and wave velocity imagings depict the changes in activity of cracks during rock fracture from temporal and spatial perspectives,respectively:the activity of cracks is strengthened,and the rate of AE events increases during rock fracture;correspondingly,the low-velocity zones are gradually aggregated and their area gradually increases.From the wave velocity imagings,the damaged zones in rock were divided into an initially damaged zone,a progressively damaged zone,and a fractured zone.During rock fracture,the progressively damaged zone and the fractured zone both develop around the initially damaged zone,showing a typical localization effect of the damage.By capturing the spatial development trends of the progressively damaged zone and fractured zone in wave velocity imagings,the development of microfractures can be predicted,exerting practical significance for determining the position of the main fracture.

Manufacturing Localization,Technology Backfire,and Economic De-globalization

Since the global financial crisis,global value chain(GVC)have been contracting amid the trend toward economic de-globalization.With GVC participation rate in mind as the core indicator of economic de-globalization,in this paper we create a multi-country general equilibrium model to characterize the mechanism by which manufacturing localization affects GVC participation rate.Our theoretical derivation shows that changes in the local manufacturing status of final products in various countries directly influence the GVC participation rate of those countries.When the local proportion of a country’s final products reaches a certain level,rising local proportion of intermediate inputs,economic growth below the world average level,and technology progress all cause the country’s GVC participation rate to decline,giving rise to de-globalization at the manufacturing and trade levels.We further provide a comprehensive interpretation based on an empirical test of the deep-seated causes of economic de-globalization in relation to such economic phenomena as increasing trade concentration,the“technology backlash”effect of the new industrial revolution,and economic growth driven by the combined forces of trade protectionism and quantitative easing.

On the Compilation Modes of Local History of Science and Technology——A Case Study of the History of Ba-Shu Science and Technology

The contents of"Ba-Shu History of Science and Technology"take up a single volume of A General History of Ba-Shu Culture.This paper attempts to explore compilation modes of the history of local science and technology by analyzing the compilation of"Shu History of Science and Technology".There are three approaches available,i.e.a general history-based approach,a discipline-based approach and an integrated approach,also known as a discipline-specific approach based on general history.This paper considers the integrated approach to be the most feasible as it elaborates Ba-Shu culture as a sub-culture of Chinese culture,the connotations of Ba-Shu achievements in science and technology,the special significance of the history of Ba-Shu science and technology,as well as the latest progress in studying the history of Ba-Shu science and technology.This paper also puts forward a possible choice to better approach the compilation of the history of local science and technology,reveals areas worth improving,and indicates a proper direction to move towards.

Delimiting the consolidation area for supplementing prime farmland with GIS technology

In view of the fact that consolidation area for supplementing prime farmland （CASPF） is a new concept proposed in the latest round of general land use planning in China, this paper proposes a new and integrated GIS- based technology for delimiting CASPF. Taking the advantage of the features of CASPF, a comprehensive evaluation indicator system for defining ordinary farmland as CASPF is established in this study, which covers 11 indicators, including slope, land plots connectivity, altitude, surface soil texture, and so on. With the help of the ideal-point method, ordinary farmland plots are sorted according to their evaluation scores in descending order. Based on the space analysis technique of GIS, high-ranking land plots are defined as CASPF reasonably.

Underwater Localization for Multiple AUVs Based on Bearing and Range Measurements

A novel underwater localization algorithm for autonomous underwater vehicle(AUVs) is proposed. Taking aim at the high cost of the traditional "leader-follower" positioning,a "parallel" model is adopted to describe the localization problem. Under an unknown-but-bounded assumption for sensor noise,bearing and range measurements can be modeled as linear constraints on the configuration space of the AUVs. Merged these constraints,a convex polyhedron representing the set of all configurations consistent with the sensor measurements can be induced. Estimates for the uncertainty in the position of a single AUV or the relative positions of two or more AUVs can then be obtained by projecting this polyhedron into appropriate subspaces of the configuration space. The localization uncertain region for each AUV can be recovered by an approximation algorithm to realize underwater localization for multiple AUVs. The deduced theoretically and the simulated results show that it is an economical and practical localization method for the AUV swarm.

Research on WSN Double-Radius Localization Algorithm Based on Partition Judgment Mechanism

Localization technology is an important support technology for WSN(Wireless Sensor Networks). The centroid algorithm is a typical range-free localization algorithm, which possesses the advantages such as simple localization principle and easy realization. However, susceptible to be influenced by the density of anchor node and uniformity of deployment, its localization accuracy is not high. We study localization principal and error source of the centroid algorithm. Meanwhile, aim to resolve the problem of low localization accuracy, we proposes a new double-radius localization algorithm, which makes WSN node launch periodically two rounded communications area with different radius to enable localization region to achieve the second partition, thus there are some small overlapping regions which can narrow effectively localization range of unknown node. Besides, partition judgment mechanism is proposed to ascertain the area of unknown node, and then the localization of small regions is realized by the centroid algorithm. Simulation results show that the algorithm without adding additional hardware and anchor nodes but increases effectively localization accuracy and reduces the dependence on anchor node.

Desulphurization Technology in China Is Maturing Day by Day

In China, a number of power plants are installed with large imported FGD equipment. As from 1990s, China has built several demonstration projects with wet limestone-gypsum, simplified wet limestonegypsum, spray semi-drying, seawater, LIFAC and EBA processes along with vigorous introduction of foreign FGD equipment and technologies. As seen by FGD projects being under invitation for bid, large-sized units will generally be fitted with limestone-gypsum FGD equipment. Although theefficiency of FGD equipment is being raised rapidly, especially that of limestone/gypsum FGD equipment can reach 90%, such a technology has much room for improvement. In the coming ten years, China should exert itself to institute design and construction specification and standards, improve operation and maintenance techniques and develop new materials, etc.

The Research Application of 3D Laser Scanning Technology in the Deformation Detection of Large Cylindrical Oil Tank

In order to ensure the safety in using a large cylindrical storage tank,it is necessary to regularly detect its defonnatioii.The traditional total station method has high accuracy in determining the deformation,however,it has a low measxirement efficiency.Long-term observation means,there are more risks in the petrochemical plant,therefore,this paper proposes the usage of the 3D laser scanner,replacing the traditional total station to determine the defbnnation of a large cylindrical storage tank.The Matlab program,is compiled to calculate the point cloud data,while the tank deformation is analyzed from two different points which are,the local concave convex degree and the ovality degree.It is concluded that,the difference between the data obtained by 3D laser scanning,and total station is within the range of oil tank deformation limit,therefore,3D laser scanner can be used for oil tank deformation detection.

应用AIM/Local中国模型定量分析减排技术协同效应对气候变化政策的影响

IPCC评价报告全面分析了温室气体减排政策措施所产生的对改善当地环境的协同效应 ,但目前国际上对国内环境保护政策措施所产生的减少温室气体排放的协同效应的研究还很缺乏 ,而后者更符合广大发展中国家的实际情况。应用区域能源环境经济综合评价模型 ,考虑现行技术及未来技术发展、当地环境保护政策和未来经济发展等因素 ,并结合对北京市的案例研究 ,来定量分析减排技术的这两种协同效应对我国气候变化政策的影响 。

Telebroadcasting of a Cat-like State via Local Operations

The quantum telebroadcasting of a cat-like state in combination with the quantum teleportation and the local copying of entanglement is presented. This gives a general way of distributing entanglement among distant parties. All of the operations of our scenario are local and within the reach of current technology.

Rolling velocity and relative motion of particle detector in local granular flow

The velocity of a particle detector in granular flow can be regarded as the combination of rolling and sliding velocities.The study of the contribution of rolling velocity and sliding velocity provides a new explanation to the relative motion between the detector and the local granular flow.In this study,a spherical detector using embedded inertial navigation technology is placed in the chute granular flow to study the movement of the detector relative to the granular flow.It is shown by particle image velocimetry(PIV)that the velocity of chute granular flow conforms to Silbert’s formula.And the velocity of the detector is greater than that of the granular flow around it.By decomposing the velocity into sliding and rolling velocity,it is indicated that the movement of the detector relative to the granular flow is mainly caused by rolling.The rolling detail shown by DEM simulation leads to two potential mechanisms based on the position and drive of the detector.

因地制宜发展新质生产力的必要性、科学性及着力点

因地制宜发展新质生产力是习近平总书记就如何发展新质生产力提出的新要求,为各地发展新质生产力提供了基本遵循、指明了方法路径。因地制宜发展新质生产力重要且迫切,体现在其为实现高质量发展提供强劲推动力、为推进中国式现代化注入新鲜活力、为培育国际竞争新优势把握新机遇、为完善现代化产业体系提供坚实支撑、为贯彻落实新发展理念指明前进方向。因地制宜是习近平总书记始终强调并亲自践行的方法论,是坚持实事求是的重要方法、是立足中国国情的现实选择、是统筹发展全局的前提条件、是避免产能过剩的关键举措。因此,因地制宜发展新质生产力应立足本地资源禀赋和优势条件,以整合科技创新资源,研发通用底层技术;释放数据要素潜能,推进区域协同创新;坚持全面深化改革,打通束缚发展堵点;调整优化金融供给,减轻企业融资压力;完善招才引智体系,锻造人才中坚力量为着力点,加快培育各具特色的新质生产力。

超长滤袋局部加密对滤袋表面过滤风速分布的影响

针对超长滤袋表面过滤风速沿其轴向分布极为不均的问题,采用数值模拟方法探究了超长滤袋局部加密对滤袋表面过滤风速分布的影响,为提升超长滤袋袋式除尘器的过滤性能寻求解决方法。结果表明:当超长滤袋未进行局部加密时,滤袋表面过滤风速沿其轴向自上而下呈递减趋势,最大过滤风速高达3.18 m/min(设计过滤风速为1.0 m/min),对应过滤风速分布均匀性指数为0.122,过滤风速分布极不均匀,此时滤袋顶部受到高速气流的冲刷作用明显;当对超长滤袋顶部30%长度滤袋进行局部加密后,滤袋表面过滤风速分布均匀性得到显著提升;当局部加密孔隙率由85%降至60%时,滤袋表面过滤风速分布均匀性指数由0.037先增至0.518后降至0.434,对应除尘效率并不受影响;当局部加密孔隙率取值为65%时,滤袋表面最大过滤风速降至2.1 m/min,此时过滤风速分布均匀性指数达到最大值0.518。

绿色技术创新对我国碳减排的影响——基于省级区域面板数据的实证分析

为了早日实现“碳达峰碳中和目标”,我国提出要建立健全绿色低碳循环发展的经济体系,而绿色技术创新是推动绿色高质量发展的关键核心,也是解决我国现实生态环境问题的重要支撑。为了研究绿色技术创新对地区碳减排的影响机制,文章基于我国30个省份2011-2020年的面板数据构建固定效应模型,并检验了能源利用率的中介机制和地方政府竞争的调节作用。研究发现,绿色技术创新可以显著促进碳减排,但这一促进作用在我国东部地区最显著,而在中部地区和西部地区不显著;进一步研究发现,绿色技术创新可以通过提高能源利用率促进碳减排,但地方政府竞争对绿色技术创新的促进作用起到负向调节作用。本研究为提高我国绿色技术创新能力、助力“双碳目标”的实现以及促进地方政府有序竞争提供了理论支撑和对策建议。

双线改革联动:数字技术与政府组织何以适配——以广东省Y区数字政府建设为例

在地方政府数字化转型过程中,数字技术与政府组织的适配是以二者获得“刚柔兼备”的可互构性为前提的。作为地方政府改革过程中具有重要能动性的机制,党的引领统合机制与印象政绩激励机制,分别具有调节政府组织刚性、提升数字技术弹性的功能。借助双线改革联动的关键契机,这两种功能互补的组织能动性机制在数字技术与政府组织的交互过程中共同作用,促成适配。地方数字政府建设的纵深推进,是对地方政府自身变革能力的一种考验,需要改革者充分考虑政府各项改革之间的关联性、耦合性,有意识地形成改革合力,促成数字政府建设与政府自身改革的同频共振、联动互补。

土特产科技服务机制创新与模式重构——以江苏葡萄产业为例

为实现创新驱动和高质量发展亟需创新机制和模式,破解科技服务“最后一公里”难题。在对新时期农业科技服务供需变化进行总体把握的基础上,通过解析江苏葡萄产业的结构性矛盾,厘清乡村特色产业科技服务的内涵要求和矛盾体现,总结凝练了各地根据区域产业特点、经济发展水平、科技资源分布等要素条件形成的科技服务创新模式,挖掘了土特产科技服务的内生机制和重构条件,为优化农业科技资源配置、提升农业科技服务质效提供政策建议。

“文化+科技”发展下泰州地区旅游项目设计分析

文化与旅游产业融合发展已经成为必然趋势,科技是文旅融合发展的联接手段,科学技术的创新运用能够为文化和旅游融合发展赋予新能量,促进文旅融合发展。立足泰州地方经济发展,对泰州区域内有代表性的旅游景区、景点进行实证调查研究,为泰州地区旅游景区、景点运用高新技术实现文化与旅游深度融合发展提出可操作性建议,使泰州的历史文化资源得到更加充分的利用和发扬传承,促进泰州文化旅游经济的进一步发展。

电力系统中的雷电暂态感知、监测和应用

雷电是造成电力系统故障的首要原因,实现对雷电暂态电压电流信号的感知、监测和数据应用对于维护系统安全稳定运行具有重要意义。面向日益复杂的新型电力系统结构形态,传感器件在满足雷电宽频测量的基础上,监测装置正朝着微型化、高精度、强互联和易取能方向发展。因此,该文基于雷电暂态感知方法、监测装置关键技术和雷击数据统计应用的研究现状,首先介绍了基于不同原理的电压/电场和电流/磁场传感技术,并分析了各自的优缺点;其次梳理了传感器微型化、时间同步、通信和供能等关键技术的最新进展;随后通过对雷击暂态波形的统计分析,探讨了监测数据在雷击故障识别与定位中的应用;最后对电力系统中雷电暂态感知、监测与应用进行总结并对其发展趋势作出展望。

面向未知环境的自主无人机智能感知测量技术

智能化测绘的发展对数据采集高效性、完备性和智能性提出了更高的要求。尤其是在林下等GNSS拒止环境下,现有传统手段往往难以完成高效率、高覆盖率测量。为了满足未知环境的智能化感知测量需求,以无人机为移动平台,本文设计并提出了一种融合视觉在线自主定位及全局探测路径规划的自主无人机智能感知测量技术与总体框架。本文首先设计并采用了一种基于点线特征的VIO(visual-inertial odometry)在线定位算法,通过点线特征的提取和匹配进行初始位姿的解算,之后利用因子图优化实时地输出无人机高精度的位姿信息。进一步地,为了实现无人机对于未知环境高效且高覆盖率的自主测量,采用了一种顾及多层次信息的全局最优探测路径规划方法确定局部最佳探测目标,然后通过轨迹搜索和优化算法实时地生成高质量的探测运动轨迹。通过自主搭建无人机平台对该技术框架进行了验证,分步对比和总体真实试验表明框架设计并采用的定位及空间探测方法相较于目前具有代表性的方法具有明显优势,并且在GNSS拒止局部林下环境中实现了高效高覆盖率的全自主测量,为未知场景进一步的在线智能化感知奠定了良好的理论方法与框架基础。