Amplitude-squared squeezing of the generalized odd-even coherent states of the anharmonic oscillator in a finite-dimensional Hilbert space

This paper discusses the properties of amplitude-squared squeezing of the generalized odd-even coherent states of anharmonic oscillator in finite-dimensional Hilbert space. It demonstrates that the generalized odd coherent states do exhibit strong amplitude-squared squeezing effects in comparison with the generalized even coherent states.

Improving landscape Characteristics in Port Said’s El Sallam Garden via Observational and Space Syntax Analysis

This paper provides a comprehensive examination of El Sallam Garden in Port Said City,concentrating on its landscape characteristics and potential for design enhancement.This study looks at how space syntax can be used to assess the impact of a tree planting design’s spatial configuration on an urban park’s visual fields.Trees play an important role in determining the spatial characteristics of an outdoor space.According to space syntax theory,an urban area is a collection of connected spaces that can be represented by a matrix of quantitative properties known as syntactic measures.Computer simulations can be used to measure the quantitative properties of these matrices.This study uses space syntax techniques to assess how tree configurations and garden area which can affect the social structures of small-scale gardens in Port Said.It also looks at how these techniques can be used to predict the social structures of four garden zones in El Sallam Garden.The study includes an observational and space syntax study through comparative analysis of four garden zones in El Sallam garden.The results of the study show that the area and planting configurations of the garden had a significant effect on the syntactic social and visual measures of the urban garden.The conclusions and recommendations can be a useful tool for landscape architects,urban planners,and legislators who want to enhance public areas and encourage social interaction in urban settings.

Variable dimensional state space based global path planning for mobile robot

A variable dimensional state space（VDSS） has been proposed to improve the re-planning time when the robotic systems operate in large unknown environments.VDSS is constructed by uniforming lattice state space and grid state space.In VDSS,the lattice state space is only used to construct search space in the local area which is a small circle area near the robot,and grid state space elsewhere.We have tested VDSS with up to 80 indoor and outdoor maps in simulation and on segbot robot platform.Through the simulation and segbot robot experiments,it shows that exploring on VDSS is significantly faster than exploring on lattice state space by Anytime Dynamic A＊（AD＊） planner and VDSS is feasible to be used on robotic systems.

Uncalibrated Path Planning in the Image Space for the Fixed Camera Configuration

基于图象的视觉 servoing 能被用来高效地控制机器人操纵者的运动。什么时候起始并且然而，需要的配置是远的是由许多研究人员，指出了如此的一条控制途径能由于它的本地性质受不了集中和稳定性问题。由指定足够的图象特征轨道在图象被列在后面，我们能利用基于图象的视觉 servoing 的本地集中和稳定性避免这些问题。因此，路径在图象空间计划是在最近的年里的机器人学的一个活跃研究话题。然而，几乎所有为 camera-in-hand 配置的盒子相关结果被建立。在这篇论文，我们建议 uncalibrated 为改正照相机配置的盒子的视觉路径计划算法。这个算法在射影的空格直接计算图象特征的轨道以便他们与僵硬天体运动兼容。由把旋转和翻译的射影的代表分解成他们的各自的正规形式，我们能容易插入内推他们在射影的空间的路径。然后，在图象飞机的图象特征的轨道能经由射影的路径被产生。这样，特征点的知识组织并且照相机内在的参数没被要求。验证建议算法的可行性和表演，基于 puma560 机器人，操纵者在这被给的模拟结果糊。

Effect of Space Charge on the Propagation Path of Air Gap Discharge

The existence of space charge may be addressed as one of the reasons that could cause shielding failure of transmission lines. In order to study the effect of space charge on discharge propagation path, a new experimental system, including mainly DC high voltage generator, impulse voltage generator as well as rod-plane electrode, has been established. The space charge was generated around the rod by means of pre-applying DC high voltage, and the air gap dis- charge experiments were conducted with and without pre-applying DC high voltage, respectively. Meanwhile, high speed cameras worked simultaneously from the front and lateral side to record the discharge propagation path so as to obtain the curvature. After statistical analysis, it is shown that the curvature increases in the middle and lower portions of the propagation path when the effect of space charge is taken into account.

Quadratic Programming-based Approach for Autonomous Vehicle Path Planning in Space

Path planning for space vehicles is still a challenging problem although considerable progress has been made over the past decades.The major difficulties are that most of existing methods only adapt to static environment instead of dynamic one,and also can not solve the inherent constraints arising from the robot body and the exterior environment.To address these difficulties,this research aims to provide a feasible trajectory based on quadratic programming（QP） for path planning in three-dimensional space where an autonomous vehicle is requested to pursue a target while avoiding static or dynamic obstacles.First,the objective function is derived from the pursuit task which is defined in terms of the relative distance to the target,as well as the angle between the velocity and the position in the relative velocity coordinates（RVCs）.The optimization is in quadratic polynomial form according to QP formulation.Then,the avoidance task is modeled with linear constraints in RVCs.Some other constraints,such as kinematics,dynamics,and sensor range,are included.Last,simulations with typical multiple obstacles are carried out,including in static and dynamic environments and one of human-in-the-loop.The results indicate that the optimal trajectories of the autonomous robot in three-dimensional space satisfy the required performances.Therefore,the QP model proposed in this paper not only adapts to dynamic environment with uncertainty,but also can satisfy all kinds of constraints,and it provides an efficient approach to solve the problems of path planning in three-dimensional space.

A Note on Calculation of Phase Space Path Integral by Means of Invariants

In this note we use the method of invariant to calculate the phase space path integral appearing in our previous article.

Phase Space Path Integral Method for Problem of Obtaining Propagator of a Particle with a Force Quadratic in Velocity

This article uses the phase space path integral method to find the propagator for a particle with a force quadratic in velocity. Two specific canonical transformations has been used for this purpose.

The Best Walking Recommendation Path by Considering the Quality of Street Space

Walking is a healthy and green way of travel,and seeking the best recommended route is the first choice for residents to travel.In this paper,according to actual demand of pedestrians,convenience,safety,comfort and appreciation are taken as different walking needs,to construct the evaluation system of urban street space quality.Combining the shortest path algorithm,the modified walking time cost of road section and intersection delay are used as impedance,obtaining the best walking recommendation paths of convenience,safety,comfort and appreciation between the beginning and the end.Moreover,the form of questionnaire survey is used for experimental verification of final recommended path.This paper could provide residents with walking path planning scheme under different needs.When guaranteeing travel efficiency,it could effectively improve walking quality of residents,with important significance for improving the attraction of green travel mode,providing diverse selectivity,and improving residents’ health.

Research on the Campus Space Cognition and Active Path of Peking University Students

Questionnaire survey and investigation were carried out to get students’feelings and cognition about campus of Peking University Shenzhen Graduate School,and active paths of their daily routine were analyzed to fi gure out the relationship between cognition and path.Characteristics of the students’space cognition and time-space active path were analyzed,and the causes of these characteristics explored to summarize the laws of students’daily life,and provide references to know psychologic status of students.

We Live on a Small Space Comet: The Third Extraordinary Motion of Earth towards the North Pole and Its Various Effects

The idea of research started with a crazy imaginary theory in the field of astrogeography, saying: We often taught ourselves and then convinced the students that the planet Earth moves despite not feeling the vibrations of traffic, and we listed successive scientific confirmations to indicate the rotation of the planet in a regular movement around its axis once every 24 hours, and it is running in another second movement around the sun once every 365¼ days, so are they only two movements, no more?! Is it possible for him to run at a regular speed in an additional direction?

基于产品空间分析的我国水果产品国际竞争力提升研究

基于路径依赖理论,使用2000—2020年联合国商品贸易数据库的新鲜水果类数据,构建中国水果产品的空间结构图,分析中国水果产品空间的路径依赖表征。研究发现:我国水果产品生产和出口存在明显的路径依赖特征;水果产品生产和出口的既成路径对国际竞争力的提升既有促进作用,又有抑制作用。据此,依托生产要素禀赋,巩固和强化比较优势,创造竞争优势是我国水果产业发展路径的必然选择;优化产业发展环境是提高我国水果产品国际竞争力的重要保障;加强企业管理创新,是提高我国水果产品国际竞争力的重要途径。

高校思想政治教育有效融入生活空间的价值意蕴、主要障碍与路径优化

生活空间是开展思想政治教育的基本场域,是思想政治教育实现空间转换的切入点。有效融入生活空间,是提升高校思想政治教育亲和力的关键,是增强高校思想政治教育针对性的重要方式,更是实现高校思想政治工作全方位育人的必然要求。高校思想政治教育与大学生生活空间的有效融合是应然的合理状态,但在融合过程中面临着由于异质性冲突导致的空间疏离、受传统路径制约和对个体需求关注不足引发的空间脱域、受网络圈层化影响形成的空间壁垒等障碍。因此,高校思想政治教育有效融入生活空间,需要基于现实生活空间加强沟通互动与情感融入,搭建好融入生活空间的桥梁中介,充分发挥文化育人、实践育人的重要作用,进一步增强思想政治教育网络空间的主导权与话语权,从而实现从疏离到融合、从脱域到互嵌、从壁垒到通达,使其在生活空间有效融入中实现自身的价值使命。

大运河沿线省市文旅商产业融合发展研究——基于耦合协调、时空演进与发展路径分析

推动大运河沿线省市文旅商产业融合和高质量发展,是有效衔接国家重大发展战略的重要抓手。通过构建文旅商产业评价指标体系,测算大运河沿线省市2012-2020年文旅商产业耦合协调度,分析空间演化特征和影响路径。研究发现:研究期内大运河沿线省市文旅商融合水平整体呈现出逐年上升趋势;文旅商融合水平不同,且具有空间集聚性;在政策保障基础上及文旅商相关因素影响下,文旅商产业通过交叉、渗透和重组,从而实现产业协同发展形成文旅商产业综合体。因此,应采取差异化文旅商融合发展策略,以区域协同发展为基础,以大运河文化带建设为抓手,进一步推动大运河沿线省市形成全域统筹、区域协同的文旅商融合发展格局,实现大运河沿线省市经济社会文化高质量发展。

中国式现代化进程中集市助推城乡融合发展问题研究——基于山东阳信集的考察

中国式现代化的宗旨是实现全体人民共同富裕,其基本路径之一是推动城乡深度融合发展。位于鲁西北地区的阳信集有着悠久的历史,在推动当地城乡融合发展过程中发挥了重要作用。基于阳信集的案例,借助社会空间视角,从过程性、关系性、要素性三方面分析集市助推城乡融合发展的过程是一种新的探索。从过程性的维度来看,集市是实现城乡空间结构重组与整合、控制与赋权的关键场域;从关系性的维度来看,集市是城乡居民进行社会互动与交往的公共生活空间;从要素性的维度来看,集市是推动劳动力、资本、信息等城乡生产要素自由流动和城乡基本公共服务一体化的交换空间。在中国式现代化发展进程中,集市已成为推动城乡融合发展的重要空间载体。

城市中心区轨道交通站点步行接驳路径特征及优化

轨道交通站点步行接驳路径特征研究,对提升轨道交通承担率具有重要意义。基于百度时空大数据API,运用空间分析法、情景模拟法、视觉语义分割法,以天津市营口道站点为例,构建城市中心区轨道交通站点步行接驳路径特征分析方法,挖掘步行接驳路径特征并揭示成因,提出针对性的优化对策。研究表明,目标站点步行接驳效率南部高于北部,具体表现在路段重复率分布均匀度南部大于北部,差异路径分布数量北部多于南部,超过3/4路径的非直线系数偏高;除站点周边区域外,接驳路径品质西北部优于东南部,具体表现在西北部视觉出行环境建设最优,区域整体设施服务水平良好。根据步行接驳路径特征,提出路网结构调整、道路断面优化、出入口调整、绿化品质提升的优化对策。

基于在线地图路径循迹的山地城市绿色开放空间步行可达性衰减

【目的】精准客观地评估山地城市绿色开放空间的步行可达性,揭示实际可达性与理论可达性之间的衰减状态,为山地绿色开放空间服务能力优化提升提供依据与参考。【方法】以重庆市渝中区为研究范围,依托ArcGIS平台和高德地图应用程序接口(application programming interface,API),引入路径循迹法,从实际步行路径出发量化可达性,并通过对比实际可达性与理论可达性来分析城市整体及绿色开放空间的可达性衰减状态。【结果】1)渝中区绿色开放空间步行可达范围整体衰减面积比为43.19%,且5 min、10 min、15 min阈值内可达范围的衰减面积比分别为32.12%、46.49%、46.30%;2)绿色开放空间衰减程度不均衡,衰减程度大于60%的绿色开放空间有16个,衰减程度最高为87.71%;3)山顶、各级台层和滨江楔形绿色开放空间的高衰减比例相对更高。【结论】进一步从选址、环境和本体3个方面总结衰减原因,并从步行可达性视角提出增量、串联、渗透的山地城市绿色开放空间优化建议,为客观评估山地城市绿色开放空间步行可达性提供思路,对山地城市绿色开放空间服务效能提升具有重要的现实意义。

制氢厂房氢泄漏激光检测光路布置优化研究

氢气扩散能力强、燃烧速度快、可燃范围广的特点使其泄漏易发生爆炸事故。对比基于可调谐半导体激光吸收光谱技术的激光传感器布置方式,以降低对氢泄漏的检测时间,获得最佳光路布置间距和角度。利用数值模拟研究了氢气在制氢厂房内的泄漏逸散规律,通过光学仿真确定了激光传感器的最短布置距离,分析了相邻光路间距及光路投影角度两种因素对氢泄漏检测的影响,得到了检测时间短、经济成本相对较低的布置方式。结果表明:相邻光路间距为0.4 m、光路与地面夹角为45°时,检测氢气泄漏时间优于其他方式并且所需激光传感器数量最少。

约束空间工业机器人姿态搜索及避障研究

为解决约束空间下机器人无碰撞目标姿态求解问题,提出一种机器人姿态快速搜索算法,并结合4种不同的路径规划算法实现工业机器人的多目标路径规划。首先,对机器人运动框架初步配置完成后,通过计算位姿矩阵得到了场景内物体坐标的动态相对关系,并在ROS中搭建规划场景;其次,提出一种基于模型和机器人逆解的机器人姿态快速搜索算法RFP,并在RoboDK中对其进行验证,验证结果表明该算法有效;最后,根据任务需求设计了路径规划流程并引入二次规划减少算法随机性的影响,提高规划成功率,应用了RRT等算法进行对比分析,仿真结果表明RRT-connect算法的规划速度与成功率高于其它算法,为样机的实现奠定了基础。

基于空间句法的矿井应急疏散研究与应用

地下矿井作业危险,空间拓扑结构复杂,因而矿山安全事故时有发生,合理的应急疏散路线规划以及疏散指示布置,能够有效提高井下人员的逃生效率,降低人员伤亡与财产损失。结合某地下矿井实例,基于空间句法和GIS网络分析搭建地下矿井巷道网络模型,从逃生人员的空间认知角度出发,利用标准化角度选择度值选取巷道网络模型中的前景网络和背景网络作为主要避险通道,为应急疏散指示标志布置提供参考;考虑巷道宽度、巷道类型、巷道坡度等巷道基础属性信息,并结合空间句法指标——标准化角度整合度,构建巷道网络应急脆弱模型,顾及巷道空间单元的稳定性,规划井下人员的最优认知路径,进而实现了多目标的地下矿井紧急疏散路线规划。该研究不仅能够为地下矿井的巷道布局设计提供建议,还可为地下矿井的应急疏散路线规划辅助决策、应急预案制定提供理论依据,同时为紧急避险系统的建设与完善提供新的思路。