An empirical study of the impacts of operating and market conditions on container-port efficiency and benchmarking

Despite the growing amount of research on container-port efficiency and benchmarking, the literature on the subject is yet to provide stable and consistent results across researchers and in relation to dynamic operating and market conditions. In this paper, we formulate a number of operational hypotheses to test the sensitivity of benchmarking results to port market and operating conditions namely production scale, cargo mix, transhipment ratio, operating configurations, and working procedures. A series of data envelopment analysis (DEA) models are used to measure the operational efficiency of 420 container terminal decision-making units from 2004 till 2010. The results show that variations in operating conditions highly impact terminal efficiency and that future work on container-port performance and benchmarking should take into account the structure and mechanisms underpinning the operations of container ports and terminals.     

A slacks-based network DEA efficiency analysis of European airlines

Conventional data envelopment analysis (DEA) models consider a system as a single-process ‘black box’. There are, however, DEA approaches that consider a system as composed of distinct processes or stages, each one with its own inputs and outputs and with intermediate flows among the stages. In this paper, a network DEA approach to airline efficiency assessment is presented. One conclusion of the study is that the network DEA approach has more discriminative power than the single-process DEA approach and that the computed targets, efficiency scores and rankings are more valid. This is because network DEA allows for a more fine-grained analysis that leads to a more realistic estimation of the overall system production possibility set than the one assumed by conventional DEA. In other words, compared with network DEA the conventional, single-process DEA represents an aggregated analysis that merges all system processes with their inputs and outputs and ignores their internal flows. The main drawbacks are the need for more detailed data (i.e. at the process level) and the greater complexity of the resulting models, especially if there are inputs or outputs that are shared among the processes.     

Performance assessment of transport services with the ERM-NDEA model: evidence from a domestic airline in Taiwan

Abstract

This paper estimates comprehensive operational performance measures for transport services. A network efficiency approach is used to analyze the production efficiency, service efficiency, and operational efficiency in a unified framework to reflect the transportation service characteristics of airline operations. We show how a modified version of the network data envelopment analysis model can be utilized for evaluating the performance of air route operations. This study considers 15 air routes operated by a domestic airline in Taiwan to highlight the value of the approach. The results of the analysis show the inputs and consumed outputs leading to production inefficiency and service inefficiency respectively as well as the magnitudes of excesses and shortfalls.     

微波除冰关键技术及应用前景分析

由冻雨形成的冰层由于与路面粘结强度大,普通除冰除雪机械无法清除,微波除冰技术可以对冰层与路面接触处进行加热,使冰层与路面分离,实现快速除冰.但是微波除冰技术的应用存在微波利用率低,设备复杂等难点.对钛酸钡加入沥青混凝土之后的微波吸收效率进行了试验,得知加入钛酸钡后混凝土对微波的吸收效率有明显提高,并指出微波除冰技术的研究应该注意微波加热设备的灵活利用和将微波除冰技术纳入综合除冰除雪体系.     

边界层理论在推移质采样器率定比尺效应研究中的应用

以MB-II型推移质采样器为例,应用边界层理论,通过计算天然状态及模型率定时采样器出口断面处由边界层引起的相对面积损失,阐明模型试验测得的水力效率较原型偏小的原因。     

以跨运车替代拖挂车的集装箱码头工艺方式

随着跨运车技术的发展,跨运车工艺方式有利于提高码头作业效率的优势得到重视,采用跨运车替代常规的拖挂车和集装箱门式起重机工艺方式中的拖挂车,不但能够提高码头作业效率而且车辆配置的成本降低。     

柴油机大功率双转子气动马达的优化设计与实验分析

以2.2 kW、15 kW等双转子气动马达的设计为例,针对齿轮式气动马达的结构特点,采用多目标函数对其齿轮转子进行了计算机优化设计,得出了可靠合理的设计参数。同时对2.2 kW气动马达的性能进行了实验分析,并对气动马达的气流通道设计作了初步的分析、探讨。为今后更大功率的气动马达的设计使用提供参考。     

基于可靠性和维修性的舰艇动力装置系统效能分析

确立动力装置的系统边界和系统状态,运用WSEIAC模型确定动力装置系统效能与其主要组成系统的可靠性和维修性之间的关系,通过灵敏度分析给出其关系曲线并进行了分析,得出动力装置主要组成系统的最佳可靠性和维修性参数值,拓展了WSEIAC模型的应用范围,对于开展舰艇动力装置效费分析具有参考价值。     

网络中心战通信网络的效能分析

随着“网络中心战”从设想开始走向现实,对网络中心战通信网络的效能进行评估并分析其对作战效能的影响,具有重要的理论和现实意义。通过分析影响通信网络效能的相关因素,通过有效性向量、可信性矩阵和品质因素向量计算的方法,建立通信网络效能评估模型。     

项目经理工作绩效的控制

从理性角度出发,分析了影响项目经理工作绩效的主要因素,并着重分析了项目经理岗位竞争程度、薪酬收入和个人声誉影响三种因素;并基于此,构建了一个描述项目经理工作绩效的多参数方程组数学模型,并进行了分析讨论;最后,还对如何提高项目经理的工作绩效控制效果提出了一些对策建议。