国外汽车自动停车系统的介绍与分析

在汽车拥有量急剧增长和停车空间尤为紧张的今天,自动停车技术将为人们生活带来极大的便利.本文介绍了国外现有自动停车系统的发展概况,并分析自动停车系统的基本结构和应用范围,以供相关技术人员学习和参考.     

Automatic parking trajectory planning based on random sampling and nonlinear optimization

The current parking trajectory planning algorithms based on geometric connections or formulation of optimization problems in automatic parking systems have strict requirements on the starting position, lower planning efficiency and discontinuous curvature of the reference trajectory. In order to solve these problems, a hierarchical planning algorithm which is combined with nonlinear optimization and the improved RRT* algorithm (Rapidly-exploring Random Tree Star) with Reeds-Shepp curve is proposed in this paper. First, the improved RRT*RS algorithm with the rapid repulsion-straddle experiment is designed for enhancing the efficiency of path planning. Second, because of the shortcomings of the Reeds-Shepp curve that can meet the minimum turning radius but not realize the continuous curvature of the path, a nonlinear optimization problem based on convex-set obstacle constraints is formulated and solved. Finally, simulation results show that the proposed parking trajectory planning algorithm in this paper can plan an effective parking trajectory with continuous curvature in different starting positions and multiple parking scenarios.     

Coalescing drops in microfluidic parking networks: A multifunctional platform for drop-based microfluidics

Multiwell plate and pipette systems have revolutionized modern biological analysis; however, they have disadvantages because testing in the submicroliter range is challenging, and increasing the number of samples is expensive. We propose a new microfluidic methodology that delivers the functionality of multiwell plates and pipettes at the nanoliter scale by utilizing drop coalescence and confinement-guided breakup in microfluidic parking networks (MPNs). Highly monodisperse arrays of drops obtained using a hydrodynamic self-rectification process are parked at prescribed locations in the device, and our method allows subsequent drop manipulations such as fine-gradation dilutions, reactant addition, and fluid replacement while retaining microparticles contained in the sample. Our devices operate in a quasistatic regime where drop shapes are determined primarily by the channel geometry. Thus, the behavior of parked drops is insensitive to flow conditions. This insensitivity enables highly parallelized manipulation of drop arrays of different composition, without a need for fine-tuning the flow conditions and other system parameters. We also find that drop coalescence can be switched off above a critical capillary number, enabling individual addressability of drops in complex MPNs. The platform demonstrated here is a promising candidate for conducting multistep biological assays in a highly multiplexed manner, using thousands of submicroliter samples.     

Considering the influence of queue length on performance improvement for a new compact robotic automated parking system

With the development of the BI (Business intelligence) applications, robots and robot-based technology appear in various fields. Compact robotic automated parking system will facilitate the informatization and modernization of urban development and environmental protection. Compact robotic automated parking (CRAP) system is a new system with higher storage utilization and rapid response to store and handle cars. This system has double storage rings, instead of one storage ring in old compact automated parking (CAP) system for storing cars in each tier, and each tier is equipped with inner rotating ring and tier-captive automated guided vehicle for horizontal transport. The CRAP system has one elevator with vertical automated guided vehicle in the outer ring instead of the center part in the old CAP system for vertical transport. We first estimate the system performance using queuing network models. Second, we validate the analytical models through simulation and a real case. The simulation results show that we make an accurate estimation. Third, we optimize system configurations by minimizing the car retrieval time. Finally, given the same storage capacity, we compare the car retrieval time based on a real application and footprint area of CRAP system with CAP system. The results show that the car retrieval time can be reduced by at least 29.7% when the system capacity C is 400, and the space utilization can be improved by at least 32.0%.     

科学的本质是否就是权力

法兰克福学派从科学的社会功能上论证,认为现代科技已政治化为一种意识形态;SSK的科学政治学派则将政治权力转换为“学科规训”概念,而从内在构成要素上对科学与政治的关系加以论证,结论是:任何现代学科都通过规训形式使“权力”渗透到其研究活动中,“权力”是科学知识的起源和内在因素,权力本身成了知识的标志。然而,科学事实上并非彻头彻尾的“权力”。科学中的政治因素不可完全排除,但这并不导致两者关系中地位的等同甚至颠覆。科学知识或说科学本质仍以客观性为主,政治因素等主观性则处于被支配的地位。     

几种感应加热电源调功方式的比较

对目前应用于感应加热领域中的几种常见的功率调节控制方法进行了分析比较．指出了各自的优缺点.     

软力量以及如何经营中国的软力量

在目前关于中国软力量的众多讨论中,有人认为中国缺乏软力量;有人认为,外国有的软力量,中国也都具备,中国是软力量大国。实际上,问题的关键在于中国如何使用和经营好软力量。国内软力量问题的研究比较突出地注意到了地区性乃至全国范围的思考。虽然中国软力量问题的研究还有很多不足,如何经营好中国的软力量才刚刚起步,但基于中国独特的社会现状的软力量问题研究,应该为国际政治和经济等方面的发展做出有中国特色的贡献。     

壬丘市电力局开展供电所标准化建设

本文从开展标准化建设的原因入手,介绍了供电所标准化建设的具体内容,标准化建设的目的,以及具体是如何开展供电所标准化建设的。     

配网自动化系统在青岛电网的应用

配电网是电力系统中最后一个直接面向用户供电的环节,用户能否得到安全可靠经济优质的电能,配电网的建设水平起到极为重要的作用,本文详细讨论了配电网自动化的构成、具备的功能及在配电网自动化建设过程中所遇到的技术问题,并结合青岛市电网的具体情况,介绍了青岛地区配电自动化系统建设的各个环节及应用。     

Power load identification

The number and power of loads that pollute the electric network, from an electric point of view, are constantly increasing. For this reason this study aims to define a parameter to assess, in terms of distortion and unbalance, the quality of an electric network. Taking as a starting point the advantages and limitations of wavelet methods proposed in the literature, a new index useful to quantify the load characteristics is introduced. The efficiency of this index has been verified by computer simulations to assess the applicability of the method to three-phase systems using three-wire measurements based on the instantaneous power theory, in several typical situations.     

从国家软实力到企业软实力

本文从软性资本、软技术、软环境集成的角度讨论了软实力的内涵和形成过程,分析了提升企业软实力的方向、途径和措施,并指出提升软实力是一个长期积累的过程.最后作为升华软实力的成功案例介绍了世界未来500强.     

音与力

格式塔心理学派认为外在世界的“力”(物理的)和人内在世界的“力”(心理的)在形式结构上有一种同形同构或异质同构的关系,与元极学理论中的“天人合一”整体观契合。“力”是格式塔心理学连接外部物质世界与人的精神世界的媒介物,而“音”则是元极学沟通自然界与人的媒介物。     

无源电力滤波器在供电系统中的设计与应用

本文从无源LC滤波器的基本原理和结构入手,介绍了滤波器设计内容和步骤,再以具体的供电系统为例分析了设计的过程,并通过仿真比较了加装滤波器前后谐波的变化.     

国际电力总承包项目承揽策略分析研究

针对中国电力行业生产能力过剩、行业竞争加剧、拓展国际市场空间的需求,在分析中国电力企业在国际竞争中的优势的基础上,提出中国电力设计院承揽国际电力总承包项目的可行性,并从项目策划、前期分析、招投标、项目谈判等整个项目周期分析了承揽国际电力总承包项目的策略.分析认为:依托国家相关扶持政策,立足国际电力总承包项目,发挥企业自身优势,寻找企业发展新的增长极;电力总承包项目要从项目的前期准备开始认真策划,进行项目合理报价并掌握谈判技巧才能取得项目成功.     

关系权力:领导权力类型的拓展与辨析

从权力类型、作用基础、服从动因等方面对经典权力模型进行梳理和对比,在评述基础上指出领导权力研究应当对基于人脉关系的权力类型进一步拓展和完善;其次,归纳权力领域对人脉关系影响作用的论述,指出领导权力研究在这方面处于概念探讨阶段,需引入、融合现有关系研究;最后,对关系权力在概念界定、类型划分、作用动因、与经典权力类型的区别等问题予以探索性回答。     

抽水蓄能电站对风电调峰能力的分析

随着电网中风电比重的增加,风力发电对电网安全运行的压力不断增大,特别是对电网的调峰压力日益增大。抽水蓄能电站是解决电网调峰填谷的最佳手段。根据呼和浩特地区风力发电的现状,分析抽水蓄能电站对风力发电的调峰能力。     

科技增长的动力模型

从科技发展的繁殖力、限制力、创造力出发，建立科技增长的动力模型，并从模型中导出四个科技发展规律。     

大型电力网络异常波动下的风险控制模型仿真

大型电力设备在使用中的安全问题越来越多,特别是应对网络的电力安全风险影响最为严重,轻者造成设备死机或误动作,重者造成设备中元器件的损害,对大型电力工程造成巨大的安全隐患。为此,提出大型电力网络异常波动下的风险控制模型仿真,通过对大规模电力系统网络的分析进行网络异常检查,把大型电力网络分解成若干较小的子网络,对每个网络在分割的边界处分别进行等值计算,通过计算值进行风险评估及建立控制模型,进行电力网络异常的风险控制的过程。仿真实验表明,大型电力网络异常波动下的风险控制模型仿真能够有效的提高电力安全的控制,降低安全风险且具备计算简单故障与复杂故障的性能,加快风险评估的速度及准确性,可靠性较强。有效的为大型电力网络异常波动提供更好的风险控制保障。