从全民阅读看基层图书馆的推动作用

推动全民阅读是一个长期的系统工程。而基层图书馆是社会文化服务体系建设中的一个重要职能部门,对全民阅读起着推波助澜的作用。本文阐述了基层图书馆对全民阅读的推动作用,分析了基层图书馆当前发展中的不足,并从服务理念、资源共享、队伍建设等几个方面提出了充分发挥基层图书馆推动作用的几点建议。     

直线电机式悬架电流滞环控制策略研究

本文设计出一种电流滞环控制策略,通过跟踪直线电机式悬架控制系统输出的最优阻尼力转变,得到参考电流,经过空间矢量调制后输出PWM波,输送到电流逆变器中转换为三相电流,进而控制直线电机的作用。经过仿真可以得出电流滞环控制策略控制效果良好,可以输出理想的阻尼力,为电动汽车主动悬架的研究提供基础。     

西北地区太阳能分时段供暖应用的研究

近年来太阳能技术发展迅速,但受低温严寒天气的影响,西北地区应用太阳能供暖有一定的局限性。通过调查、统计和分析西北地区典型城市气象资料,结合对各种太阳能设备工作条件应用效果的总结,得出了各种太阳能设备应用的最佳时间,提出严寒地区太阳能分时段应用的概念。由此形成太阳能综合利用于西北地区热水和供暖项目的方案,为太阳能技术在西北地区的发展开拓新途径。     

Modelling shared space users via rule-based social force model

The promotion of space sharing in order to raise the quality of community living and safety of street surroundings is increasingly accepted feature of modern urban design. In this context, the development of a shared space simulation tool is essential in helping determine whether particular shared space schemes are suitable alternatives to traditional street layouts. A simulation tool that enables urban designers to visualise pedestrians and cars trajectories, extract flow and density relation in a new shared space design, achieve solutions for optimal design features before implementation, and help getting the design closer to the system optimal. This paper presents a three-layered microscopic mathematical model which is capable of representing the behaviour of pedestrians and vehicles in shared space layouts and it is implemented in a traffic simulation tool. The top layer calculates route maps based on static obstacles in the environment. It plans the shortest path towards agents’ respective destinations by generating one or more intermediate targets. In the second layer, the Social Force Model (SFM) is modified and extended for mixed traffic to produce feasible trajectories. Since car movements are not as flexible as pedestrian movements, velocity angle constraints are included for cars. The conflicts described in the third layer are resolved by rule-based constraints for shared space users. An optimisation algorithm is applied to determine the interaction parameters of the force-based model for shared space users using empirical data. This new three-layer microscopic model can be used to simulate shared space environments and assess, for example, new street designs.     

静强度全工况计算分析与应用

文章针对多载荷工况的静强度计算结果,利用FEM软件的二次开发语言和混合编程技术,引入静强度全工况计算及可视化的图形显示,分析全部静强度载荷工况下的材料利用度和其它性能指标参数,对结构的整体静强度性能进行全面、高效、准确地评估,并以重载机车车体为例进行静强度全工况计算的应用研究。     

Analysis of Ocean-Space and Sea-Level Rise Policy in Two Coastal Cities

Global sea-level rise (SLR) is among the most alarming aspects of anthropogenic climate change. The human impacts of SLR are experienced unequally between and within municipalities. Existing research has identified social variables that predict municipal adoption of adaptive SLR policy, but this work does not account for the locally specific social factors that shape particular policies to fit particular cases. This study describes social conceptions of the ocean and SLR policy for two coastal cities in western Washington: Aberdeen and Bainbridge Island. Examining conceptions of marine spaces provides insight into the complex process by which local physical and socio-demographic characteristics shape local policy. The study uses a grounded theoretical approach to content analyses, resulting in localized typologies of marine spaces as well as SLR policy profiles for each case. Results indicate that municipalities vary by both social conception of the ocean and SLR policy form. These findings elaborate upon the relationship between socioeconomic conditions and municipal climate change policy adoption, suggesting that in local media and policy discourse, the absence of relevant resources is related to adversarial conceptions of local marine spaces, while abundance of relevant resources is associated with a conception of marine spaces as natural resources.     

基于状态空间采样的高速公路智能网联车辆轨迹动态规划

为实现智能网联车辆在高速公路动态行车环境下的轨迹实时规划，提出一种基于状态空间采样的轨迹动态规划方法。首先，以安全性为原则选取主车当前行驶的理想车道。基于Frenet坐标与笛卡尔坐标的转换关系，建立车辆运动横、纵向解耦的独立积分系统。将高速公路常见的行驶状态分为车道保持与定速巡航、变道以及前车跟随3类，预测主车行驶车道并针对3类行驶状态分别设计轨迹终端的目标配置方法。然后，利用多项式函数生成连接初始配置和目标配置的多条待选轨迹。构建考虑轨迹偏离理想车道程度、始末速度变化、规划周期和轨迹舒适性的综合损失函数，结合速度、加速度、曲率检查来评价各条待选轨迹的成本并进行排序。最后，预测车辆的横、纵向运动轨迹并构建一种胶囊形的车辆虚拟安全边界，通过碰撞检测，确定主车的最优轨迹，设置动态规划触发条件及时更新最优轨迹并避免过度规划浪费资源。研究结果表明：提出的算法能满足高速公路场景的动态规划需求；通过对轨迹规划周期、虚拟安全边界、动态规划时间间隔等关键参数的分析与优化，主车的横摆角速度范围稳定在-0.1~0.15 (°)·s^-1，横向加速度范围稳定在-0.16~0.32 m·s^-2，跟踪参考轨迹的最大误差不超过0.022 m，提出的算法能规划出具有高安全性、稳定性和舒适性的轨迹。     

国内装备维修保障资源优化技术研究综述

通过对国内有关维修保障资源优化文献的回顾,分析了在决策方法、需求预测、配置优化等方面的研究现状和特点,认为未来的维修保障资源优化技术将要更多的考虑费效比和纳入复杂多因素的影响作用,并向综合化、信息化方向发展。     

城市轨道交通工程技术专业教学资源库建设的研究与实践

创建城市轨道交通工程技术专业教学资源库,其有助于共享优质教学资源,提高专业教学质量,为实现自主学习和终身学习搭建公共平台,是国家骨干高职院校建设的重要内容之一。广东交通职业技术学院着眼于为学生、教师和企业员工三方创造良好、方便的学习、资源分享环境,从专业标准库、课程资源库、虚拟实训库、专业素材库、职业信息库、专业竞赛与学生作品库、社会服务与培训平台、顶岗实习与就业管理平台等9个方面建设城市轨道交通工程技术专业教学资源库。     

“五位一体”的管理模式在高校资源建设中的应用

文中从数据、文件、档案、信息和知识集成化管理的角度,探讨了“五位一体”的知识管理和知识服务理念在高校资源建设中的应用。