Analysis of Mobile and Internet Network Coverage: Propagation of Electromagnetic Waves and Concept of Digital Divide in Burundi

Mobile and Internet network coverage plays an important role in digital transformation and the exploitation of new services. The evolution of mobile networks from the first generation (1G) to the 5th generation is still a long process. 2G networks have developed the messaging service, which complements the already operational voice service. 2G technology has rapidly progressed to the third generation (3G), incorporating multimedia data transmission techniques. It then progressed to fourth generation (4G) and LTE (Long Term Evolution), increasing the transmission speed to improve 3G. Currently, developed countries have already moved to 5G. In developing countries, including Burundi, a member of the East African Community (ECA) where more than 80% are connected to 2G technologies, 40% are connected to the 3G network and 25% to the 4G network and are not yet connected to the 5G network and then still a process. The objective of this article is to analyze the coverage of 2G, 3G and 4G networks in Burundi. This analysis will make it possible to identify possible deficits in order to reduce the digital divide between connected urban areas and remote rural areas. Furthermore, this analysis will draw the attention of decision-makers to the need to deploy networks and coverage to allow the population to access mobile and Internet services and thus enable the digitalization of the population. Finally, this article shows the level of coverage, the digital divide and an overview of the deployment of base stations (BTS) throughout the country to promote the transformation and digital inclusion of services.

Mapping Rural Mobility in the Niakhar Area (Fatick Region, Senegal)

Despite the development of information and communication technologies, mobility still remains an important factor in the development of the social capital, by promoting social interactions. However, rural African populations face more difficulties getting around than city dwellers. In addition, studies on mobility in Africa are relatively weak. In rural African areas, this ignorance of mobility is even more important. It is necessary to identify the characteristics and the spatial structure of mobility flows before starting any reflection on solutions, particularly in terms of spatial allocation of transport resources. Our main objective is to map the current movement flows in the Niakhar area. We chose to use the cartographic approach to analyze mobility flows. The data come from a survey carried out in 2018, as part of the French Institute of Research for Development (IRD) Niakhar Atlas project. For the data analysis, we used 4 methods: dominant flux method, net flux calculation method, directional mean statistics and areal interpolation. The results revealed differences in mobility behavior depending on the season and in space, and the existence of three dominant centers: Ngayokhème, Diohine and Toucar. They also made it possible to highlight the main directions of the flows and the scalar fields of mobility.

Transmission in mobile cloudlet systems with intermittent connectivity in emergency areas

The recent development of Mobile Cloud Computing has helped in solving numerous real-life problems. The rate of growth of mobile devices has been increasing at a very high pace. Mobile devices have made substantial contributions in managing emergency situations. Owing to the mobility of mobile devices, cloudlets, and their intermittent connectivity, it may become very difficult to handle emergency situations. To address this problem, a transmission model is proposed for mobile cloudlet systems, where a mobile device is used to designate a cloudlet by using the Borda scores Method and the mobile device can offload a part of its application to this cloudlet. The simulation results demonstrated that the proposed work makes a significant comtribution toward alleviating the problems associated with emergency situations.

Localized Coverage Connectivity Based on Shape and Area Using Mobile Sensor Robots in Wireless Sensor Networks

A wireless sensor network (WSN) is spatially distributing independent sensors to monitor physical and environmental characteristics such as temperature, sound, pressure and also provides different applications such as battlefield inspection and biological detection. The Constrained Motion and Sensor (CMS) Model represents the features and explain k-step reach ability testing to describe the states. The description and calculation based on CMS model does not solve the problem in mobile robots. The ADD framework based on monitoring radio measurements creates a threshold. But the methods are not effective in dynamic coverage of complex environment. In this paper, a Localized Coverage based on Shape and Area Detection (LCSAD) Framework is developed to increase the dynamic coverage using mobile robots. To facilitate the measurement in mobile robots, two algorithms are designed to identify the coverage area, (i.e.,) the area of a coverage hole or not. The two algorithms are Localized Geometric Voronoi Hexagon (LGVH) and Acquaintance Area Hexagon (AAH). LGVH senses all the shapes and it is simple to show all the boundary area nodes. AAH based algorithm simply takes directional information by locating the area of local and global convex points of coverage area. Both these algorithms are applied to WSN of random topologies. The simulation result shows that the proposed LCSAD framework attains minimal energy utilization, lesser waiting time, and also achieves higher scalability, throughput, delivery rate and 8% maximal coverage connectivity in sensor network compared to state-of-art works.

Application of Wireless Local Area Network Technology in Mobile Robot for Finned Tube Inspection

This paper introduces a novel robot for outer surface inspection of boiler tubes. The paper describes the hardware system, wireless communication strategy, communication procedure and system software of the robot. The WLAN technology is used in the robot. It solves the problem of shielding generated by iron boiler and 11Mbps bandwidth made it possible for video and control stream real-time transmit within the same channel. Though TCP/IP protocol is robust, serial server is a transparent channel but cannot detect error and retransmit the data. In order to improve the reliability of serial communication, a new communication protocol is proposed. Key words boiler tubes - mobile robotics - wireless local area network Project Supported by the National High-Tech Program (Grant No. 2002AA420080)

Research Proposal: A Study of the Effect of Mobile Dictionary Use on English Learning: Focusing on the Students in Vocational School in Rural Area

Mobile devices are effective tools for language learning and have positive effect on the development of language skills,heighten learners’ language learning attitudes and motivation, and support learner interaction, collaboration, and the coconstruction of knowledge. In spite of the popularity of mobile dictionaries among students, research on the effect of this app on students’language learning, especially focusing on the students from vocational school in rural area, is still scarce. So the purpose ofthe current study is probing into the effect of using mobile dictionaries on lower-intermediate students’ language learning, focusingon the students from vocational school in rural areas, in contrast to using printed dictionaries. This proposal is arranged as follows:section one presents the research background; section two reviews literatures; section three provides research problems and research design; section four presents data analysis and anticipated results. This proposal ends with conclusions. In term of researchaims, a mixed method of quantitative and qualitative will be applied with the main aim of probing the effect of using mobile dictionaries on students’ English learning and the opinions of students’on using the mobile dictionaries in English learning. Researchmethods in the form of quasi-experimental pre-and post-tests, questionnaires, interview will be undertaken to collect data.

四川地区流动重力观测及其在地震预测中的应用

通过回顾四川地区测网变迁和震例总结,客观阐述四川流动重力观测的发展历程及其在地震趋势判定中的应用效能。结果表明,利用流动重力资料观测到高梯度带、四象限分布、零值线拐弯等重力场时变异常信号,对川滇菱形块体内部及边界带发生的汶川地震、芦山地震、九寨沟地震、泸定地震等地震进行了准确的中期预测,尤其在强震地点判定上预测效果较好,准确率达60%。

政策变迁对粤港澳大湾区人口流动的影响研究

自2019年《粤港澳大湾区发展规划纲要》正式出台至今,粤港澳大湾区在珠三角城市群的基础上结合港澳优势已发展成为中国开放程度最高,经济活力以及人口集聚能力最强的城市群之一,在国家发展大局中具有重要的战略地位。粤港澳大湾区与国内其他城市群相比,人口迁移流动除了受到户籍制度的影响,还受到社会制度差异的制约。采用双重差分方法对粤港澳大湾区人口流动进行实证分析的结果表明,粤港澳大湾区建设的提出以及《粤港澳大湾区发展规划纲要》的出台对于粤港澳大湾区人口流动具有显著的促进作用,从具体政策影响来看,创业就业政策、税收支持政策以及优质生活政策对于粤港澳大湾区人口流动的促进作用更具直接性。由此,要实现粤港澳大湾区生产要素特别是人口和劳动力高效便捷流动,实现大湾区转型发展、创新发展,仍需要进行制度和政策创新,在就业、税收、优质生活、通关服务以及人才引进等方面出台更多切实有利于人口流动、劳动力资源优化配置的政策,如建立统一的公共服务平台、统一个人所得税税收征收标准、提升生活便利度等措施。

基于手机信令数据的贝叶斯优化出行链识别

为了克服手机信令数据定位信息的时空不确定性对出行识别的影响,分析手机信令数据的时空特性,在时空阈值识别停留点方法的基础上,引入兴趣面(AOI)信息和基站位置数据,提出可变参数滑动窗口的出行停留点识别方法.建立出行链模型,采用贝叶斯多目标优化获得模型的最佳参数,实现时空阈值的动态调整,提高识别的准确性.为了验证方法的有效性,组织志愿者采集真实出行GPS数据和出行信息标签作为验证数据,与应用模型于对应手机信令数据后的结果进行对比.研究结果表明,手机信令数据的采样在移动和静止状态下存在特性差异;相较于对比方法,提出的出行链识别方法在泛化性能和最优性能方面都表现出较小的误差和较高的识别率,尤其在识别率指标上,相比其他的最新算法改进了3%~26%.

新时代农村重大社会风险治理的动员机制与生成逻辑

社会动员能够在短期内最大程度上整合治理资源,成为中国应对复杂问题的重要方式。农村重大社会风险治理关键在于形成强有力的社会动员机制。新时代农村重大社会风险治理实践中,动员网络、动员方式、主体互动机制都呈现诸多新变化,既发挥党组织的组织优势,又发挥政府的专业化优势,同时根据治理情境变化,能动性调整动员策略,最大程度激活体制内外各种力量参与,是党政统合的社会整合动员机制。党政统合的社会整合动员机制有其内生逻辑,它是执政党基因、公共权力基因、公益基因、社会责任基因等多元基因融合的结果,是新时代中国特色社会主义社会动员机制的新呈现。

戏剧与动员:闽西苏区红色戏剧的革命化实践

闽西苏区红色戏剧产生于特定的历史条件下。作为中国共产党进行宣传教育的重要手段,其不仅仅是一种综合性的舞台艺术,更是中国共产党进行革命的艺术武器,是革命文化的重要组成部分。红色戏剧以其特殊的方式反映现实,通过化装表演、活报剧、话剧、歌舞剧和戏曲等多种形式支持社会革命,兼具娱乐大众与教育教化的功能,并在发展过程中不断实现娱乐化向革命化的转变,进一步成为中国共产党宣传动员的重要工具。

结构性团体心理-运动干预对农村独居老年人的影响

目的探讨结构性团体心理-运动干预对农村独居老年人孤独感、老化态度及生活空间移动性的效果。方法采用抽签法将湖州市织里镇2个村随机分为2个组,在各村采用便利取样法招募独居老年人各32人,对照组接受乡镇卫生中心开展的常规健康管理,干预组在常规基础上进行每周1次,共12周的结构性团体心理-运动干预。采用多维孤独感量表、老化态度问卷、生活空间评估量表测评老年人的孤独感水平、老化态度及生活空间移动性。结果12周干预后,干预组老年人孤独感总分及其各维度得分显著低于本组干预前及对照组干预后,老化态度、生活空间移动性得分显著高于本组干预前及对照组干预后(均P<0.05)。结论结构性团体心理-运动干预能够有效缓解农村独居老年人孤独感和负性老化态度,提高老年人的生活空间移动性。

基于移动多线激光雷达扫描的树冠叶面积估计方法

移动单线激光雷达(Laser detection and ranging,LiDAR)扫描(Mobile single-layer LiDAR scanning,MSLS)树冠叶面积估计方法使用单一视角的单线激光雷达采集树冠点云数据,获取的冠层信息不够全面,限制了树冠叶面积估计精度。本文提出一种基于移动多线LiDAR扫描(Mobile multi-layer LiDAR scanning,MMLS)的树冠叶面积估计方法,使用多线LiDAR从多个视角采集树冠点云数据,提升树冠叶面积估计精度。首先,将多线LiDAR采集的点云数据变换到世界坐标系下,通过感兴趣区域(Region of interest,ROI)提取出树冠点云。然后,提出一种MMLS树冠点云融合方法,逐个融合单个激光器采集的树冠点云,设置距离阈值删除重复点,添加新点。最后,构建MMLS空间分辨率网格,建立基于树冠网格面积的树冠叶面积估计模型。实验使用VLP-16型多线LiDAR传感器搭建MMLS系统,设置1、1.5 m 2个测量距离和间隔45°的8个测量角度对6个具有不同冠层密度的树冠进行数据采集,共得到96个树冠样本。采用本文方法,树冠叶面积线性估计模型的均方根误差(Root mean squared error,RMSE)为0.1041 m^(2),比MSLS模型降低0.0578 m^(2),决定系数R^(2)为0.9526,比MSLS模型提高0.0675。实验结果表明,本文方法通过多线LiDAR多视角树冠点云数据采集、MMLS树冠点云融合和空间分辨率网格构建,有效提升了树冠叶面积估计精度。

以“乐”施“教”:苏区文艺功能价值论

苏区文艺在第二次国内革命战争时期,并非仅仅是一种活跃苏区军民文化生活的艺术形态,而是作为传播无产阶级革命思想最重要的宣传工具,自觉地承担起了推动中国革命走向胜利的三大使命:一是通过革命启蒙,唤醒了苏区军民的阶级意识,并以“打土豪、分田地”为政治纲领,彻底解决中国农村中分配不公的土地问题,目的就是要建立一个由人民当家作主的民主国家;二是通过战争动员,使广大农民群众真正了解第二次国内革命战争的伟大意义,并从思想上明确保卫苏维埃革命政权,就是在保卫贫苦农民已经到手的胜利果实,进而充分调动他们参加这场革命战争的积极性;三是通过统战工作,瓦解国民党军队的内战士气,团结一切爱国力量,建立抗日民族统一战线,进而全力以赴去保卫中华民族的美丽家园。苏区文艺这三大功能价值,在中国现代革命的具体实践中,已经成为一种红色文艺的光荣传统。

左右江革命根据地政治动员的实践、成效及当代启示

左右江革命根据地时期,红七军前委、左右江地方党组织认真贯彻执行党中央关于宣传、发动、教育、组织、武装群众的策略方针,在壮族、瑶族等少数民族人口占多数的左右江地区进行了卓有成效的政治动员,推动了左右江革命根据地各项事业的发展,为党在少数民族地区开展群众工作积累了实践经验。探讨左右江革命根据地政治动员的目的和内容、实践、经验与当代启示,有利于传承和弘扬革命精神、拓展政治动员的理论内涵,对凝聚正能量以中国式现代化全面推进中华民族伟大复兴有着重要的历史借鉴意义。

基于改进两步移动搜索法的合肥市中心城区综合公园可达性评价

为提高城市综合公园布局均衡性地定量评估的准确性,以合肥市中心城区为例,提出一种基于改进多出行模式的两步移动搜索法,利用高德地图的路径规划模型,结合双变量局部空间自相关、洛伦兹曲线以及基尼系数等方法,在手机信令数据的基础上对不同时间阈值下的城市综合公园的可达性及供需情况进行分析,进一步揭示中心城区综合公园布局的合理性。结果显示:合肥市中心城区综合公园的可达性空间差异显著,可达性较高区域通常分布在新城区以及综合公园周边地区,并且随着时间阈值的提高,可达性水平的空间分布呈现均衡态势;合肥市中心城区在15 min与30 min时间阈值下均只有近5%的居住网格处于供需匹配状态;近7%的居住网格处于供需显著不匹配状态,主要集中于老城区西部以及滨湖区北部区域,居住区密度与综合公园数量是影响供需匹配的重要原因。研究结果表明,通过利用手机信令数据与高德路径规划数据作为数据源对传统可达性的计算方法以及两步移动搜索模型进行改进,建立微观尺度下城市综合公园的可达性评价框架,能够精确地评估城市综合公园的可达性;通过优化城市交通的通达程度以提高居民综合公园游憩出行的阈值,能够显著促进城市综合公园整体的空间分布合理性。

东南沿海传统村落人口外流格局及驱动机制的微观研究

该文以浙闽粤三省959个国家级传统村落为样本,综合运用加权核密度估计、克里金插值等方法,在村级尺度多维刻画东南沿海传统村落人口外流的空间格局,利用相关系数和地理探测器定量探测影响因子的作用,进而从地理资本视角分析影响因子的作用机理并构建驱动机制。结果表明:①东南沿海传统村落人口外流的地形分异和山区集聚格局显著,重心位于闽北山区,核心源区位于浙西南山区;②地形条件、人地关系、城村联系和经济收入是影响人口外流率村际差异的显著因子,人均耕地面积与其他因子的协同作用是主导驱动力;③传统村落人口外流是海拔、坡度、地形起伏度等7个显著因子协同作用的结果,是生态资本、区位资本和经济资本的函数。

南京都市圈跨市日常人口流动影响因素及其空间效应研究

跨市日常人口流动逐渐成为衡量都市圈一体化水平的重要因素,其不仅受到本地社会经济环境的影响,也受到邻近地区发展的空间效应影响,但目前对其影响因素及空间效应的讨论相对较少。因此,文章对其影响因素及其空间效应进行研究。研究发现:①南京都市圈跨市日常人口流动规模和节点控制力分别形成了以南京市为核心向外围扩散和以边界区域为核心沿主要交通走廊分布的空间格局。②其分布具有空间依赖性,流动规模主要体现在周边区域对空间单元的随机冲击,节点控制力主要体现在周边区域中介作用提升对本区域的空间溢出作用。③影响其空间格局的因素较为复杂,流动规模受到公服设施、交通建设、经济社会属性多种类型的因素影响,而节点控制力则主要与公服设施、交通建设相关。研究进一步丰富了日常人口流动的研究内容,既从空间效应维度对其形成机制进行补充,也为跨区域人口流动引导体系的构建提供了依据。

三峡库首区蓄放水重力效应模型的构建与观测

通过高分遥感影像精确提取三峡库首区水体边界,对水体部分构建精密的离散化数值模型,模拟计算三峡库首区在不同蓄放水位产生的重力效应,并对秭归站2017年gPhone 101重力仪与茅坪站2019~2021年gPhone 113重力仪的连续观测数据进行精细预处理。结果表明,在145~175 m蓄水过程中,模拟得到不同蓄水高度(间隔5 m)对岸边的重力变化值分别为0~28μGal、0~47μGal、0~60μGal、0~97μGal、0~170μGal、0~210μGal。当蓄水位升高5 m时,离岸2 km范围内存在10~20μGal的影响;当蓄水位升高30 m时,离岸5 km范围内存在30~40μGal的影响。重力残差主要反映水文重力效应信息,秭归站重力残差记录到约40μGal的重力变化,茅坪站重力残差记录到约50μGal的重力变化,重力变化趋势和水位变化呈现非常好的一致性,验证了模型模拟结果的准确性,可为三峡库首区及其岸边稳定性监测提供参考。

中国数字人才空间分布与流动格局——基于京津冀、长三角和粤港澳地区的分析

人才是数字经济发展的核心驱动力。通过梳理人工智能、物联网、云计算和区块链领域的关键核心技术,基于领英(LinkedIn)大数据洞察平台,获取京津冀、长三角和粤港澳地区的数字人才静态区位(2022年)和动态迁移(2021—2022年)数据,比较分析中国三大城市群数字人才分布与流动格局。结果表明:(1)数字人才高度集中在核心城市,但在能级上与顶尖全球城市还有较大差距;(2)粤港澳和长三角地区数字人才发展的协调水平高于京津冀地区,并形成了港–深、沪–苏两大高地;(3)数字人才在中国呈现环流格局,但全球尺度上是非“零和博弈”,表现出以香港地区为枢纽向海外转移的趋势;(4)三大城市群中不存在净流入型活跃城市,因而都面临严峻的数字人才流失风险。最后,从全球、区域和地方角度提出政策建议。