Forecasting demand for high speed rail

It is sometimes argued that standard state-of-practice logit-based models cannot forecast the demand for substantially reduced travel times, for instance due to High Speed Rail (HSR). The present paper investigates this issue by reviewing the literature on travel time elasticities for long distance rail travel and comparing these with elasticities observed when new HSR lines have opened. This paper also validates the Swedish long distance model, Sampers, and its forecast demand for a proposed new HSR, using aggregate data revealing how the air–rail modal split varies with the difference in generalized travel time between rail and air. The Sampers long distance model is also compared to a newly developed model applying Box–Cox transformations. The paper contributes to the empirical literature on long distance travel, long distance elasticities and HSR passenger demand forecasts. Results indicate that the Sampers model is indeed able to predict the demand for HSR reasonably well. The new non-linear model has even better model fit and also slightly higher elasticities.     

The time slot allocation problem under uncertain capacity

This paper presents two stochastic programming models for the allocation of time slots over a network of airports. The proposed models address three key issues. First, they provide an optimization tool to allocate time slots, which takes several operational aspects and airline preferences into account; second, they execute the process on a network of airports; and third they explicitly include uncertainty. To the best of our knowledge, these are the first models for time slot allocation to consider both the stochastic nature of capacity reductions and the problem’s network structure. From a practical viewpoint, the proposed models provide important insights for the allocation of time slots. Specifically, they highlight the tradeoff between the schedule/request discrepancies, i.e., the time difference between allocated time slots and airline requests, and operational delays. Increasing schedule/request discrepancies enables a reduction in operational delays. Moreover, the models are computationally viable. A set of realistic test instances that consider the scheduling of four calendar days on different European airport networks has been solved within reasonable – for the application’s context – computation times. In one of our test instances, we were able to reduce the sum of schedule/request discrepancies and operational delays by up to 58%. This work provides slot coordinators with a valuable decision making tool, and it indicates that the proposed approach is very promising and may lead to relevant monetary savings for airlines and aircraft operators.     

Interactive image-based information visualization for aircraft trajectory analysis

Objectives: The objective of the presented work is to present novel methods for big data exploration in the Air Traffic Control (ATC) domain. Data is formed by sets of airplane trajectories, or trails, which in turn records the positions of an aircraft in a given airspace at several time instants, and additional information such as flight height, speed, fuel consumption, and metadata (e.g. flight ID). Analyzing and understanding this time-dependent data poses several non-trivial challenges to information visualization.Materials and methods: To address this Big Data challenge, we present a set of novel methods to analyze aircraft trajectories with interactive image-based information visualization techniques.As a result, we address the scalability challenges in terms of data manipulation and open questions by presenting a set of related visual analysis methods that focus on decision-support in the ATC domain. All methods use image-based techniques, in order to outline the advantages of such techniques in our application context, and illustrated by means of use-cases from the ATC domain.Results: For each considered use-case, we outline the type of questions posed by domain experts, data involved in addressing these questions, and describe the specific image-based techniques we used to address these questions. Further, for each of the proposed techniques, we describe the visual representation and interaction mechanisms that have been used to address the above-mentioned goals. We illustrate these use-cases with real-life datasets from the ATC domain, and show how our techniques can help end-users in the ATC domain discover new insights, and solve problems, involving the presented datasets.     

Effect of a speed reduction of containerships in response to higher energy costs in Sulphur Emission Control Areas

The objective of this paper is to explore the possible consequences of the future low-sulphur fuel requirements in Sulphur Emission Control Areas (SECA) on vessel speed, from the standpoint of the container shipping industry. Rational energy use, speed reduction, and revenues are closely related in the container shipping sector because speed reductions may provide substantial energy and cost savings. The operators could consider reducing their speed in SECA in order to save on fuel that will become relatively expensive. However, to maintain a weekly frequency without adding new ships, such a behaviour implies that the required speed at sea outside the SECA area increases. This paper aims to investigate if such a difference in speed is cost-effective, and if the increase in speed outside SECA may result in an increase in CO₂ emissions of the total cycle. We propose a cost model that estimates the cost-minimising combination of speeds inside and outside SECA, and the resulting CO₂ emissions of the liner service. Applying this model to representative liner services serving North Europe, we find that differentiating speed accordingly slightly decreases total costs and increases CO₂ emissions in a similar way. The results are sensitive to the price of low-sulphur fuels, the part of the cycle in SECA and the number of ships deployed in the service.     

运动带钢平面上粘性流体吹扫装置——在宝钢冷轧机组上的应用

本文论述了可用于去除轧制后残存在带钢表面润滑剂的改进型喷嘴吹扫装置，实际应用表明，改进型喷嘴吹扫装置可使带钢表面乳化液斑迹次品率降低，并降低了连轧机组末级出口处的噪声。     

2 000 t沥青运输船液货系统设计

结合改装船对沥青液货系统进行分析,在沥青泵组、装卸管系、加热保温系统等方面提出几种可行的设计方案,并对这些方案作了比较;同时指出设计中应注意的一些问题。     

37 300 dwt化学品船开发与设计

为逐步完善安全、生态友好和经济的全球航运体系,本船设计贯彻新的环保设计理念。除满足各种最新公约、规则和有关法规的要求,包括MARPOL公约,SOLAS、IBC规则,USCG和OCIMF及Exxon公司等各项要求外,具有装卸时间短、极小的货油残留量、更可靠的防污染能力和高效快速洗舱等特征。     

旋风除尘CFD分析

一汽技术中心从2001年开始研制旋风筒式空气预滤器，并利用CFD进行旋风筒的分析与计算。介绍了3种不同结构除尘器的滤清效率比较；同一结构除尘器在不同空气流量下滤清效率比较；除尘器水平、垂直放置对滤清效率的影响；加装旋风除尘器后对发动机功率的影响。     

打破"诸侯经济"创双赢

上海建设国际航运中心,确定了洋山深水港的建设项目,由此带来了上海港和宁波港激烈的货源之争,而更大的竞争压力来自釜山等东北亚大型港口。面对这样的形势,上海、宁波两港应积极合作,一致对外,争取早日把上海港建成国际航运中心,同时使宁波港得到迅速发展。当“错位发展”的合作形式遇到困难时,以资本为纽带的“港口联盟”可能会是一种好的合作形式。     

全垫升式气垫船水压场试验研究

在拖曳水澉中对全垫升式气垫船的水压场进行了系统测量，得到不同水深、不同航速和不同横向位置水底振动压力系统的纵向通过特性曲线，分析总结了气垫船水压场规律。