驼峰电子化控制系统中通信技术应用的研究

结合在驼峰电子化执行模块控制系统研发中的实际经验,介绍驼峰电子化控制系统中主控机与智能电子模块间通信方式的重要性,提出一种基于EPP协议的安全可靠、实时的通信方法.     

基于总线控制的船舶机舱监测报警实训系统设计

本文介绍一种基于总线控制的网络型机舱监测报警实训系统设计方案.该系统以流行的总线控制型监测报警系统实船设备为主,辅以报警系统功能试验和报警点调试装置,整个实训系统为开展报警应答操作、功能试验、报警点调试、故障分析与排除等技能训练创造了条件.     

Analysis of real-time control strategies in a corridor with multiple bus services

Control strategies have been widely used in the literature to counteract the effects of bus bunching in passenger‘s waiting times and its variability. These strategies have only been studied for the case of a single bus line in a corridor. However, in many real cases this assumption does not hold. Indeed, there are many transit corridors with multiple bus lines interacting, and this interaction affects the efficiency of the implemented control mechanism.This work develops an optimization model capable of executing a control scheme based on holding strategy for a corridor with multiple bus lines.We analyzed the benefits in the level of service of the public transport system when considering a central operator who wants to maximize the level of service for users of all the bus lines, versus scenarios where each bus line operates independently. A simulation was carried out considering two medium frequency bus lines that serve a set of stops and where these two bus lines coexist in a given subset of stops. In the simulation we compared the existence of a central operator, using the optimization model we developed, against the independent operation of each line.In the simulations the central operator showed a greater reduction in the overall waiting time of the passengers of 55% compared to a no control scenario. It also provided a balanced load of the buses along the corridor, and a lower variability of the bus headways in the subset of stops where the lines coexist, thus obtaining better reliability for all types of passengers present in the public transport system.     

智能建筑控制总线技术浅析

现阶段建筑智能化工程中控制总线技术应用较多，但各类技术之间差别很大。本文从应用的角度简介和分析这些技术，并对其应用在建筑智能化工程中的特点进行分析，对以太网和无线网络通信技术应用在控制总线领域内的趋势和特点提出自己的意见。     

Measuring supply chain efficiency based on a hybrid approach

Supply chain management has a tremendous impact on the success of a company. One of the critical issues for gaining competitive advantages for companies is improving supply chain performance. Most studies about the application of Data Envelopment Analysis (DEA) Supply chain models do not identify the benchmarking units for inefficient supply chains. On the other, measuring the short run and long run of the supply chain efficiency is another challenge for decision makers in supply chain management. Hence, we propose a methodology of DEA for measuring of the supply chain. We integrated two approaches as special cases of the hybrid model and compare the short and long run strategies of supply chain and can be identified benchmarking.     

Optimal bus service patterns and frequencies considering transfer demand elasticity with genetic algorithm

This paper attempts to optimize bus service patterns (i.e., all-stop, short-turn, and express) and frequencies which minimize total cost, considering transfer demand elasticity. A mathematical model is developed based on the objective total cost for a generalized bus route, which is optimized subject to a set of constraints ensuring sufficient capacity, an operable bus fleet, and service frequency conservation. To optimize the integrated service of a bus route with many stops, which is a combinatorial optimization problem, a genetic algorithm is developed and applied to search for the solution. A case study, based on a real-world bus route in New Jersey, is conducted to demonstrate the applicability and effectiveness of the developed model and the solution algorithm. Results show that the proposed methodology is fairly efficient, and the optimized bus service significantly reduces total cost.     

基于耗散结构理论的乌海市公交优先必要性研究

通过对乌海市海勃湾区居民出行进行问卷调查，针对不同类型的出行者出行方式所占比例，结合以耗散结构理论为基础的公交车-小汽车出行需求竞争模型计算分析了实施公交优先的必要性。分析结果表明按照现有的出行比例及出行量来推算未来的出行分配，不加限制的自由发展和实施公交优先对城市的交通影响截然不同，在有限的道路资源前提下，实施公交优先是解决未来交通拥堵、节约能源的必由之路。     

Attribute‐based perceptual mapping using discriminant analysis in a public sector passenger bus transport company: A case study

This study aims at evaluating the customer expectations in a public sector passenger transport company, a crucial sector in developing countries like India. A questionnaire containing 18 quality characteristics was administered to various customers of three bus depots of one division of a state road transport undertaking in South India. Attribute‐based perceptual mapping using discriminant analysis was done to position the three depots and to identify their strengths and weaknesses. The findings would help prioritize different parameters and also provide guidelines for managers to focus on and to improve. Copyright © 2012 John Wiley & Sons, Ltd.     

Evaluating the long term impacts of transport policy: An initial assessment of bus deregulation

Local buses in Britain, outside London, were ‘deregulated’ as a result of the 1985 Transport Act, with most of the organisational changes implemented in 1986 but many of the ownership changes occurring over a longer period. By contrast, in London, the 1984 London Regional Transport Act introduced a system of comprehensive tendering – but it took 10 years for the organisational and ownership changes to be fully implemented. This paper examines the long term impacts of these changes. A key issue when examining long term changes is that of the counterfactual – what would have happened if the changes had not occurred? An econometric model of the demand for local bus services in Britain is outlined and used in conjunction with extrapolative methods for key variables such as fares and bus kms to determine demand-side counterfactuals. Some analyses of subsidy and of costs will also be outlined. This will then permit the examination of welfare change by estimating changes in consumer and producer surpluses, updating earlier studies. It is found that outside London, bus demand declined strongly, at least up to the year 2000 and some of this reduction can be ascribed to deregulation. By contrast in London, demand has generally been increasing. However, in both areas operating costs also declined strongly, again up to 2000, but since then there have been strong increases in costs and subsidy. Our initial finding is that there are net welfare increases both outside and inside London, but with welfare increases per capita being five times greater in London than elsewhere. However, sensitivity analysis shows that our results are sensitive to the specification of the modelling system and assumptions made concerning the counterfactual, particularly for the results for London.     

Optimizing sustainable feeder bus operation considering realistic networks and heterogeneous demand

A mathematical model is developed to optimize social and fiscal sustainable operation of a feeder bus system considering realistic network and heterogeneous demand. The objective total profit is a nonlinear, mixed integer function, which is maximized by optimizing the number of stops, headway, and fare. The stops are located which maximize the ridership. The demand elasticity for the bus service is dependent on passengers' access distance, wait time, in‐vehicle time, and fare. An optimization algorithm is developed to search for the optimal solution that maximizes the profit. The modeling approach is applied to planning a bus transit system within Woodbridge, New Jersey. Copyright © 2011 John Wiley & Sons, Ltd.