Control Logix与西门子变频器DP通讯解决方案

本文叙述了AB公司的Control Logix控制器与西门子变频器之间,通过第三方设备MVI56‐PDPMV1模块,实现Profibus总线通讯的方法和步骤。简要介绍了在建的三峡升船机系统中用到的试验设备、试验步骤、试验现象和试验结果。     

Berth assignment planning for multi‐line bus stops

In this paper, we study an important problem that arises with the fast development of public transportation systems: when a large number of bus lines share the same bus stop, a long queue of buses often forms when they wait to get into the stop in rush hours. This causes a significant increase of bus delay and a notable drop of traffic capacity near the bus stop. Various measures had been proposed to relieve the congestions near bus stops. However, all of them require considerable financial budgets and construction time costs. In this paper, with the concept of berth assignment redesign, a simulation‐based heuristic algorithm is proposed to make full use of exiting bus berths. In this study, a trustable simulation platform is designed, and the major influencing factors for bus stop operations are considered. The concept of risk control is also introduced to better evaluate the performance of different berth arrangement plans and makes an appropriate trade‐off between the system's efficiency and stability. Finally, a heuristic algorithm is proposed to find a sub‐optimal berth assignment plan. Tests on a typical bus stop show that this algorithm is efficient and fast. The sub‐optimal berth assignment plan obtained by this algorithm could make remarkable improvements to an actual bus stop. Copyright © 2013 John Wiley & Sons, Ltd.     

曲面分段车间作业排程仿真优化

曲面分段建造是船舶建造过程的重要环节之一。由于曲面分段结构差异较大、工艺流程复杂、多采用固定胎位建造等特点,对于平衡分段建造、提升造船效率具有重要影响。针对曲面分段建造特点,船厂会结合船坞搭载节点制定胎位执行计划表。本文根据某船厂曲面车间胎位执行计划表,制定初始静态胎位作业计划,采用虚拟仿真技术,建立三条固定胎位虚拟流水线,结合启发式算法进行胎位计划排程,减少最大完工时间,得到较合理的胎位作业计划表,验证了启发式优化算法排程的可行性和有效性 。     

高温超导电机力矩管性能研究

力矩管是高温超导电机中的一个重要部件,起着绝热、支撑转子并传递扭矩等多项重要作用.因此力矩管的各项性能,如绝热性能、冷收缩性能以及力学性能等,都是超导电机研制和设计中尤为重要的参量,需要进行深入分析和研究.本文从模拟计算和试验研究两个方面对高温超导电机力矩管的各项性能进行了比较分析,验证了所制作的力矩管符合设计要求,能够满足高温超导电机的需要.     

一种新型重型越野汽车的可活动上车踏板结构设计

重型越野汽车通常需要将第一阶上车踏板设计成活动的。由于重型越野汽车的使用环境非常复杂,因此活动上车踏板需要性能可靠耐用。本文所描述了这样一种新结构上车踏板。     

Numeric-based XML labeling schema by generalized dynamic method

Most efficient indeces and query techniques over XML (extensible markup language) data are based on a certain labeling scheme, which can quickly determine ancestor-descendant and parent-child relationship between two nodes. The current basic labeling schemes such as containment scheme and prefix scheme cannot avoid relabeling when XML documents are updated. After analyzing the essence of existing dynamic XML labels such as compact dynamic binary string (CDBS) and vector encoding, this paper gives a common unifying framework for the numeric-based generalized dynamic label, which can be implemented into a variety of dynamic labels according to the different user-defined value comparison methods. This paper also proposes a novel dynamic labeling scheme called radical sign label. Extensive experiments show that the radical sign label performs well for the initialization, insertion and query operations, and especially for skewed insertion where the storage cost of the radical sign label is better than that of former methods.     

杭州市“错峰限行”交通需求管理措施实践

为全面科学地评价杭州市"错峰限行"交通需求管理措施的实施效果并总结实施经验,对措施的决策、实施与效果评估等进行研究。首先,介绍各项措施的具体内容和出台背景。然后,阐述决策过程中的考量和组织实施特色,再根据半年来的实时监测和动态评估,分析"错峰限行"措施实施后的市区交通运行状况变化和市民感受。最后指出,由于在决策和实施过程中最大限度地考虑了市民感受,"错峰限行"措施实施后不仅交通拥堵改善效果明显,更得到了大多数市民的支持。     

新型高流动混凝土砂浆材料的研制

介绍了新型高流动性混凝土砂浆粉体成分及浆体配制方法,分析了不同配比条件下砂浆的性能,得出了实用于工程实践的最佳砂浆配制方法。