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341.
ABSTRACTThis paper focuses on understanding to what extent the components of LUTI models and their mutual interactions are conceptually represented by eight operational LUTI models. This is important for the understanding of LUTI models’ mechanisms, firstly because it may reduce communication barriers between planning communities, secondly because it may help us understand the models’ applicability, and thirdly it may highlight the models’ shortcomings and point for future research. We present a discussion about what subsystems should be considered for LUTI modelling, from which we derived an “a priori” conceptual ALUTI model (incorporating Activities, besides Land Use and Transport). By comparing the rationale behind each model with this conceptual model, we establish the basis for our review, focussing on whether these models incorporate the ALUTI components, its inner workings and the relationships between these components. Results indicate three main limitations of the reviewed models. First, models not always adequately include all the components of the a priori ALUTI model. Second, the ALUTI subsystems’ internal functions are not explicitly modelled in several of the models reviewed, making it difficult to evaluate how planning decisions affect the subsystem. Third, only few models recognise all mutual interactions, especially in respect to the Activity subsystem. 相似文献
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Obrad Babić Milica Kalić Goran Pavković Slavica Dožić Mirjana Čangalović 《运输规划与技术》2013,36(3):257-280
Abstract When disturbances make it impossible to realise the planned flight schedule, the dispatcher at the airline operational centre defines a new flight schedule based on airline policy, in order to reduce the negative effects of these perturbations. Depending on airline policy, when designing the new flight schedule, the dispatcher delays or cancels some flights and reassigns some flights to available aircraft. In this paper, a decision support system (DSS) for solving the airline schedule disturbances problem is developed aiming to assist decision makers in handling disturbances in real-time. The system is based on a heuristic algorithm, which generates a list of different feasible schedules ordered according to the value of an objective function. The dispatcher can thus select and implement one of them. In this paper, the possibilities of DSS are illustrated by real numerical examples that concern JAT Airways' flight schedule disturbances. 相似文献
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机场运营效率评价及影响因素分析对科学反映中国主要民用机场运营效率现状,实现中国民航业可持续发展,提高中国机场国际竞争力具有重要意义.本研究首先利用双重导向型DEA模型测算2006-2010年中国27个主要民用机场的运营效率,然后从宏观环境、行业与区域竞争及机场特征三个方面探索机场运营效率的影响因素.研究结果表明,2006-2010年中国主要民用机场的运营效率基本维持在较高水平;各机场的运营效率自2008年始均有不同程度的下降,且机场间运营效率的差异呈现逐年增大的趋势;腹地经济、机场规模、机场级别和一市多场等因素促进了机场运营效率的提升;区域竞争和行业竞争则不利于机场运营效率的提升. 相似文献
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为了满足低电压低功耗的应用需求,本文利用MOSFET在亚阈区的超低功耗特性,实现了一种带共模反馈的亚阈运算放大器.该亚阈运算放大器结构简单,采用TSMC 0.18μm工艺实现,且工作于1.2 V电源电压下.通过Synopsys Hspice仿真,结果表明,该电路在输出负载为0.5pF时直流增益为70.97 dB、单位增益带宽6.346 MHz、相位裕度85.76°、正负压摆率分别为3.58V/μs和-3.58 V/μs,功耗仅为4.80μW. 相似文献
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如果一条线路只有一座车辆段,并设在靠近线路的端部时,必须使线路两端终点站的运营服务时间基本接近。非运营时间客车全部停放在车辆段的传统做法,使运营时间利用率低、运营与夜间维修和施工时间的矛盾日渐突出。通过对利用正线非运营时间停放过夜客车来提高运营效率的可行性研究,结合广州地铁1、2号线的现状分析,提出解决方案,可减少列车空走和司机劳动强度,提高服务水平,有效地提高正线运营效率。 相似文献