Hybrid model for prediction of bus arrival times at next station

Effective prediction of bus arrival times is important to advanced traveler information systems (ATIS). Here a hybrid model, based on support vector machine (SVM) and Kalman filtering technique, is presented to predict bus arrival times. In the model, the SVM model predicts the baseline travel times on the basic of historical trips occurring data at given time‐of‐day, weather conditions, route segment, the travel times on the current segment, and the latest travel times on the predicted segment; the Kalman filtering‐based dynamic algorithm uses the latest bus arrival information, together with estimated baseline travel times, to predict arrival times at the next point. The predicted bus arrival times are examined by data of bus no. 7 in a satellite town of Dalian in China. Results show that the hybrid model proposed in this paper is feasible and applicable in bus arrival time forecasting area, and generally provides better performance than artificial neural network (ANN)–based methods. Copyright © 2010 John Wiley & Sons, Ltd.     

浅析公路特殊路段路基防护与加固

论述公路路基一般防护与加固原则和处理措施,重点对滨河路基,风沙路基防护要求进行了介绍。     

Study on the form factor and full-scale ship resistance prediction method

To consider the resistance component due to hull geometry, the International Towing Tank Conference (ITTC) adopted the resistance test method in 1978, introducing the form factor concept with two basic assumptions, i.e., the form factor of a model ship is the same as that of a full-scale ship and the form factor is independent of ship speed. However, it is not only very difficult to determine the form factor using the ITTC ’78 method, but also there have been questions regarding the basic assumptions. Therefore, the authors carried out three basic studies on the form factor concept and proposed a new extrapolation procedure for the prediction of full-scale ship resistance performance. The validity of the proposed procedure is being investigated by comparing sea trial and model test results. The results of this investigation will be presented in the near future.     

立管卡子安装方法探讨

近年来,中国海洋石油工业发展迅猛。为了控制油田总体开发成本,新建的海上采油平台往往依托于原有平台的工艺处理和油气集输系统。这就需要铺设相应的海底管道和电缆,将新旧平台连接起来。海管和平台之间需要通过安装在导管架上的立管来连接,而用来固定立管的结构物一立管卡子的安装步骤是比较复杂的,通常需要动用大型浮吊船舶,成本高昂。本文系统地介绍了利用气动绞车安装立管卡子装方法。该方法可以不借助浮吊,有效地节约了工程成本。     

基于Profibus-DP的西门子PLC与伟肯变频器通讯的实现

本文构建了由PC机、PLC、变频器组成的基于Profibus-DP总线的控制系统。文中分析了变频器通讯的相关参数设置及Profibus-DP通讯协议,利用Step-7和NC-Drive等软件开发实现了西门子S7-300PLC与伟肯变频器的实时通讯,同时也给出了相关组态流程及源程序。试验表明系统运行稳定、可靠。     

日本三大海运巨头应对国际金融危机的策略

<正>作为日本历史悠久的3大上市海运集团,日本邮船、商船三井和川崎汽船经历了航运发展的跌宕起伏。本文简要回顾2008年国际金融危机爆发以来,这3家"百年老店"的经营状况和应对策略。1多元化经营降风险日本邮船、商船三井和川崎汽船的经营范围广泛,包括集装箱班轮运输(以下简称班轮运输)、油船运输、散货运输、物流、码头等多种业务;与其他业务相比,班轮运输业务的地位并不十分突出。     

Reliability analysis of multi-state repairable system with dynamic transition probabilities

Inadequate maintenance decisions lead to incremental overall costs. In order to minimize costs in maintenance of the multi-state repairable system, we model a preventive maintenance (PM) scheme of the multistate repairable system using non-Markov process. The periodically decreasing reliability model of the non-Markov dynamic system with dynamic transition probabilities is established to satisfy the probability change. The diesel engine system is taken as an example to illustrate the model. The reliability of the diesel engine is analyzed and its PM scheme is worked out. RENO software is used to simulate the diesel engine system. The maintenance cost of components and the optimal PM interval data of the system are obtained by using the minimal average cost as the objective function. The adaptability of PM is judged, and the optimal PM scheme is presented.     

考虑轴力和剪切效应的盾构隧道纵向变形分析

采用傅立叶级数法研究了不同荷载作用下轴力和剪切效应对盾构隧道变形的影响.?计及剪切变形所产生的地基反力,建立了弯曲变形的控制微分方程,推导了剪切变形的计算公式;采用与既有理论解对比的方法,验证了级数解的正确性;通过对比计算,分析了截面形式、端承条件、荷载形式、长高比以及有无弹性地基对盾构隧道剪切变形的影响,剪切刚度对弯...     

《公路泥石流防治工程设计指南》梗概

泥石流是山区公路的主要病害。简述了《公路泥石流防治工程设计指南》（简称《指南》）的编写背景及依据,慨述了《指南》的主要技术框架以及《指南》应用过程中应注意的几个关键问题,为公路建设及养护等相关技术规范的修改提供了重要依据。     

智能化UPS的实用通讯接口设计

智能化UPS通过增设通信接口提高了UPS的管理水平,方便地实现了远程监控。本文以TMS320系列DSP为主控芯片的智能化UPS为例,介绍其通讯接口RS-232接口及在RS-232接口基础上的SNMP接口的构建,该SNMP卡为硬件协议栈设计。本文给出了智能化UPS通讯接口相关硬件及软件设计方法。