Heat Release Rate and Temperature Field of a Bus on Fire北大核心CSCD

Bus fires are a common source of fires that occur in tunnels and are a huge threat to the safety of the tunnel structure and related personnel. An elaborate numerical simulation model of a bus is established considering the different combustion characteristics of the bus body, seats, decorations and baggage. For fires occuring at the bus head, middle part or back seat, the temperature field, heat release rate (HRR) and characteristics of the fire are ana-lyzed. The HRR calculation formula is obtained by superimposing a Boltzmann curve on a Gaussian curve. The re-sults show the peak and average values of a bus HRR are 48 MW and 8.1 MW, respectively, and the released energy due to combustion is 14.5 GJ; the maximum burning temperature reaches 1 040℃ and the temperature near the door can reach 60℃ after 120 sec. The temperature rises fastest at the bus door when the fire occurs at the rear of the bus and it has a high chance of detonating the fuel tank. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

基于VISA技术的高速USB数据采集系统

高速USB数据采集系统的设计严格遵循USB2.0协议,实现了主机和测试设备之间简单、快速、可靠的连接和通信.该文介绍了这种数据采集系统的硬件组成、驱动程序和固件程序的设计以及采用虚拟仪器软件LabWindows/CVI在VISA技术上开发应用程序的设计方法.     

基于SAE—J1939的车联网无线诊断终端产品的研究与开发

摘要：对当前车联网的发展背景进行简要介绍；并对OBD诊断技术、CAN总线技术、SAEJ39进行了较为详细的研究；提出了基于SAEJ1939的一种车联网无线诊断模块，并就模块硬件设计及应用进行了的阐述。     

An analysis of public bus transit performance in Indian cities

Maintaining and enhancing public transit service in Indian cities is important, to meet rapidly growing mass mobility needs, and curb personal motor vehicle activity and its impacts at low cost. Indian cities rely predominantly on buses for public transport, and are likely to continue to do so for years. However, the public bus transit service is inadequate, and unaffordable for the urban poor. The paper explores the factors that contribute to and affect efforts to improve this situation, based on an analysis of the financial and operational performance of the public bus transit service in the four metropolitan centres and four secondary cities during the 1990s. Overall, there were persistent losses, owing to increasing input costs and declining productivity. The losses occurred despite rapidly increasing fares, and ridership declined. The situation, and the ability to address it, is worse in the secondary cities than the metropolitan centres. We suggest a disaggregated approach based on the needs and motivations of different groups in relation to public transit, along with improved operating conditions and policies to internalize costs of personal motor vehicle use, to address the challenge of providing financially viable and affordable public bus transit service.     

计算机病毒武器：“网络中心战”的常规武器

随着美国海军“网络中心战”的提出,计算机病毒武器的研究与应用已成为各国军方关注的重大课题。本文首先讨论了计算机病毒武器的特点,然后分析了计算机病毒武器的现状和攻击样式,最后探讨了计算机病毒武器的发展趋势。     

空气悬架大客车平顺性仿真分析

应用MSC．ADAMS软件在ADAMS／Car里建立了整车动力学仿真模型，用Pro/E软件和试验的方法获得了整车动力学参数。在ADAMS／Car里进行了空气悬架大客车平顺性仿真分析，并将分析结果与试验结果进行了比较。结果表明，所建立的空气悬架大客车多体系统动力学模型。可以对空气悬架大客车整车性能做出正确的预测。     

基于MVB总线的机车安全监测系统设计

机车控制网络通过MVB总线实现机车内部各节点之间的数据交换,从而实现对机车安全高效的控制.在介绍一种基于MVB总线的机车网络的基础上,提出一种新的安全监测单元的设计构思,并阐述其中部分的设计实现.     

The impact of real-time information on bus ridership in New York City

In the past few years, numerous mobile applications have made it possible for public transit passengers to find routes and/or learn about the expected arrival time of their transit vehicles. Though these services are widely used, their impact on overall transit ridership remains unclear. The objective of this research is to assess the effect of real-time information provided via web-enabled and mobile devices on public transit ridership. An empirical evaluation is conducted for New York City, which is the setting of a natural experiment in which a real-time bus tracking system was gradually launched on a borough-by-borough basis beginning in 2011. Panel regression techniques are used to evaluate bus ridership over a three year period, while controlling for changes in transit service, fares, local socioeconomic conditions, weather, and other factors. A fixed effects model of average weekday unlinked bus trips per month reveals an increase of approximately 118 trips per route per weekday (median increase of 1.7% of weekday route-level ridership) attributable to providing real-time information. Further refinement of the fixed effects model suggests that this ridership increase may only be occurring on larger routes; specifically, the largest quartile of routes defined by revenue miles of service realized approximately 340 additional trips per route per weekday (median increase of 2.3% per route). Although the increase in weekday route-level ridership may appear modest, on aggregate these increases exert a substantial positive effect on farebox revenue. The implications of this research are critical to decision-makers at the country’s transit operators who face pressure to increase ridership under limited budgets, particularly as they seek to prioritize investments in infrastructure, service offerings, and new technologies.     

Plan-based flexible bus bridging operation strategy

Bus bridging has been widely used to connect stations affected by metro disruptions such that stranded passengers could resume their journeys. Previous studies generally assumed that a bus operates exclusively on one bridging route with given frequency, which limits the service flexibility and reduce the operational efficiency. We propose a strategy to instruct buses to operate on predefined bridging routes once they are dispatched from depots. Buses are allowed to flexibly serve different bridging routes. Each bus operates based on a bridging plan that lists the stations to serve in sequence instead of route frequencies. A two-stage model is developed to optimize the bridging plans and their assignments to buses with the objectives that balance the operational priorities between minimizing bus bridging time and reducing passenger delay. A Weight Shortest Processing Time first (WSPT) rule based heuristic algorithm is developed to solve the proposed model. The developed model is further incorporated in a rolling horizon framework to handle dynamic passenger arrivals during the disruption period. The effectiveness of the proposed strategy is demonstrated in comparison with alternative strategies in real-world case studies.     

What drives the drivers? Predicting turnover intentions in the Belgian bus and coach industry

The bus industry is characterized by demanding jobs and high turnover rates. In this study we gather essential insights that can help companies and industry-level policy makers increase the attractiveness of the profession and design effective retention policies. We compare the factors that induce Belgian drivers to leave their current organization with those inducing them to leave the industry. Key factors increasing the likelihood to consider quitting the company are a negative work-life balance, a lack of social support and a temporary contract. Dominant factors to consider quitting the bus driver profession are a lack of fulfillment, a demanding job environment and a negative work-life balance.