基于QT Quick的消息分发模型研究

QT Quick是一项新技术,用于动态设计和描述图形用户界面。文章基于QT Quick技术,提出了一种消息分发模型,并结合工程实际应用,对该模型实现的关键技术、消息分发流程进行了研究。     

基于BIM的城市轨道交通运维模型交付标准研究

结合我国城市轨道交通建设的发展现状，并基于BIM（building information modeling，建筑信息模型）技术的应用尝试与实践，阐述轨道交通交付信息标准化的重要性，提出了轨道交通设施设备BIM模型数据库的初步架构。以轨道交通运营维护管理需求为导向，调研分析轨道交通交付的设施设备对象及其信息，在21类轨道交通设施设备中确定了15类交付对象，并将交付对象的属性信息分为两大模块，即基本模块和外部链接模块，规范BIM模型建制单位提交的BIM模型成果内容。最后，探讨轨道交通建筑信息模型的交付形式，对BIM模型交付的数据格式、模型拆分与组合给出了一定的建议。     

Logistics impacts of student online shopping – Evaluating delivery consolidation to halls of residence

Growth in online shopping has led to increased numbers of small delivery vehicles in urban areas leading to a range of negative externalities. Young people are significant generators of home deliveries and, when clustered in university halls of residence, can generate considerable freight traffic to one location. This paper explores the potential to consolidate these deliveries using an urban consolidation centre. Based on the case of Southampton, UK, data were compiled from three linked sources: a delivery audit of four halls of residence at the University of Southampton housing 5050 residents; annual package receipt records from Southampton Solent University halls (2294 residents); and an online shopping survey distributed to Southampton University students (486 responses). The results suggest that in cities with multiple higher education institutions (HEIs), where in excess of 8000 students live in halls, over 13,000 courier trips could be generated annually, delivering over 4000 m³ of packages. These could be consolidated onto fewer than 300 vehicles for an annual service cost of approximately £18 per student, reducing congestion, parking infringements and improving air quality. Analysis indicated student acceptance of a consolidated parcel service but operational challenges would include enforcement, performance risk, finance and delivery speed.     

基于物联网技术的血液物证保全系统的设计与实现

本文利用物联网技术设计了血液物证保全系统,包括研发一款便携式智能血液物证送检箱和建立血液物证信息化保管平台。系统同时可使血液物证从提取到送检移交全过程密闭、低温冷藏保存,且可进行在线血液监管,较好的保全血液物证。系统同时可实现血液物证系统化、规范化保管,使血液检验结论更客观、公正,对规范酒驾、醉酒办案具有重要的支撑作用。     

Weekly container delivery patterns in liner shipping planning models

This paper addresses a fundamental question related to nearly all container liner shipping planning models: whether the implicit assumption of identical container delivery pattern every week is valid in a situation of identical shipping services and identical cargo demand every week. We prove that when the number of containers transported from one port to the next is formulated as a continuous variable, the resulting mathematical model with an identical container delivery pattern is equivalent to the model with general container delivery patterns which can be different in different weeks. When the number of containers transported is formulated as an integer variable, the model with an identical container delivery pattern is not equivalent to the model with general container delivery patterns. However, the difference between the optimal objective values of the two models is negligible for practical applications. In sum, little, if not nothing, is lost by assuming an identical container delivery pattern in liner shipping planning models.     

Can agents measure up? A comparative study of an agent-based and on-line optimization approach for a drayage problem with uncertainty

Experiments studying the behavior of agent-based methods over varying levels of uncertainty in comparison to traditional optimization methods are generally absent from the literature. In this paper we apply two structurally distinct solution approaches, an on-line optimization and an agent-based approach, to a drayage problem with time windows under two types of uncertainty. Both solution approaches are able to respond to dynamic events. The on-line optimization approach utilizes a mixed integer program to obtain a feasible route at 30-s intervals. The second solution approach deploys agents that engage in auctions to satisfy their own objectives based on the information they perceive and maintain locally. Our results reveal that the agent-based system can outperform the on-line optimization when service time duration is highly uncertain. The on-line optimization approach, on the other hand, performs competitively with the agent-based system under conditions of job-arrival uncertainty. When both moderate service time and job-arrival uncertainties are combined, the agent system outperforms the on-line optimization; however, in the case of extremely high combined uncertainty, the on-line optimization outperforms the agent-based approach.     

散装水泥半挂车罐体改进的可行性

通过对散装水泥半挂车罐体原始结构的有限元分析，提出了原始的四仓结构在使用过程中存在的问题。为解决这一问题，将罐体由原始的四仓结构改为三仓结构。     

铁路货物运输速度和逾期率的调查与分析

市场经济对铁路货物运输的时效性有较高的要求,根据1999年对铁路货物运输状态调查抽样的数据,从管内和直通运输,运价里程,品类及运价号四个方面对铁路货物运输时效性服务水平进行分析评价,针对存在的问题提出了扩大开行快运列车,强化运输组织,加强作用管理,加快信息化进程等对策以提高铁路货物运输的时效性服务水平。     

泥水盾构主机推进速度与泥浆系统能力的匹配

通过分析泥浆系统流量与盾构掘进进度关系,对泥水盾构主机推进速度与泥浆系统能力的匹配进行了阐述,为盾构采购用户提供一些参考。     

Untangling process complexity in logistics delivery services with unpredictable service sequences: a mixed-method study of chemical tanker port calls

We explore the complexity issue relevant to a logistics service process characterized by unpredictable service stages and service sequences in the context of chemical tankers’ call in the Port of Houston. The operational dimensions of uncertainty and conflict surrounding process complexity are examined through a mixed-methods approach using both qualitative and quantitative data collected from the Port of Houston. We propose a taxonomy to classify several uncertainty and conflict factors emerged from our qualitative analysis, including structural conflict, structural uncertainty, infrastructural conflict, and infrastructural uncertainty. The case study findings are validated and triangulated by a quantitative analysis which quantifies the time and cost impacts of unproductive chemical tanker movement on port-call service performance. We contribute to the complexity theory by introducing four dimensions of process complexity to the stream of process-oriented logistics service research. These four complexity dimensions can be used by managers to untangle their process complexity. Our pseudo-service-stage based mapping technique will also be valuable for managers to visualize their service processes with unpredictable service sequences. Finally, we call for future research on synchronization across operational processes between service stages.