Impact analysis of maritime cabotage legislations on liner hub-and-spoke shipping network design

Maritime cabotage is a legislation published by a particular coastal country, which is used to conduct the cargo transportation between its two domestic ports. This paper proposes a two-phase mathematical programming model to formulate the liner hub-and-spoke shipping network design problem subject to the maritime cabotage legislations, i.e., the hub location and feeder allocation problem for phase I and the ship route design with ship fleet deployment problem for phase II. The problem in phase I is formulated as a mixed-integer linear programming model. By developing a hub port expanding technique, the problem in phase II is formulated as a vehicle routing problem with pickup and delivery. A Lagrangian relaxation based solution method is proposed to solve it. Numerical implementations based on the Asia–Europe–Oceania shipping services are carried out to account for the impact analysis of the maritime cabotage legislations on liner hub-and-spoke shipping network design problem.     

Distribution-free vessel deployment for liner shipping

One important problem faced by the liner shipping industry is the fleet deployment problem. In this problem, the number and type of vessels to be assigned to the various shipping routes need to be determined, in such a way that profit is maximized, while at the same time ensuring that (most of the time) sufficient vessel capacity exists to meet shipping demand. Thus far, the standard assumption has been that complete probability distributions can be readily specified to model the uncertainty in shipping demand. In this paper, it is argued that such distributions are hard, if not impossible, to obtain in practice. To relax this oftentimes restrictive assumption, a new distribution-free optimization model is proposed that only requires the specification of the mean, standard deviation and an upper bound on the shipping demand. The proposed model possesses a number of attractive properties: (1) It can be seen as a generalization of an existing variation of the liner fleet deployment model. (2) It remains a mixed integer linear program and (3) The model has a very intuitive interpretation. A numerical case study is provided to illustrate the model.     

Application of structural equation modeling to evaluate the intention of shippers to use Internet services in liner shipping

Operations research (OR) is the application of modeling techniques to formulate and analyze systems and problems for management decision-making. Structural equation modeling (SEM) is a modeling technique applied to social or behavioral systems to understand and explain relationships that may exist among elements of systems. Recently, the measurement of unobservable variables has gained increasing attention in operations management (OM) research, and the OR discipline has begun to recognize the value of applying SEM to analyze behavioral-related OR problems. To provide OR researchers with a better understanding of the application of this useful statistical modeling technique, this paper presents a tutorial on the application of SEM. Specifically, we investigate the key factors that affect the adoption of Internet services in the context of liner shipping services. Although [Fishbein, M.A., Ajzen, I., 1975. Belief, Attitude, Intention and Behavior: An Introduction to Theory and Research, Addison-Wesley, Reading, MA; Davis, F.D., 1989. Perceived usefulness, perceived ease of use, and user acceptance of information technology. MIS Quarterly 13 (3), 319–339; Ajzen, I., 1985. From intention to actions: A theory of planned behavior. In: Kuhl, J., Bechmann, J. (Eds.), Action Control: From Cognition to Behavior. Springer Verlag, New York, pp. 11–39; Ajzen, I., 1991. The theory of planned behavior. Organizational Behavior and Human Decision Processes 50, 179–211] have made important contributions to understanding users’ behavior of technology acceptance, shippers’ resistance to end-user systems is still a common problem in the liner shipping industry. To better predict, explain, and increase shippers’ acceptance of technology, we need to understand why shippers accept or reject Internet services provided by their liner shipping carriers. Another objective of this paper is to propose and empirically test a theoretical framework that relates the intention of shippers to use Internet services in liner shipping with its antecedents such as perceived usefulness, perceived ease of use, and the perceptions of security protection. Tests of the structural model confirm Davis’s (1989) notion that perceived ease of use explains the intention of shippers to use Internet services, and that perceived ease of use has a strong positive effect on perceived usefulness. The results also indicate that security protection influences perceived ease of use. The SEM analyses in this study offer OR researchers a methodological guide on how to assess the efficacy of both a measurement model that relates observed indicators to latent factors and a structural model that poses relationships between constructs.     

基于收益共享机制的干支线衔接运输联合定价模型

在班轮运输网络中,支线运输与干线运输具有互补性,干线承运人与支线承运人之间的合作能够为托运人提供更高的便利度和更完善的运输服务。本文在考虑可替代运输路径之间竞争关系的基础上,研究干支线衔接路径的定价问题,在运输链纵向一体化和分散化两种结构下,构建Bertrand博弈模型研究上下游承运人的均衡运价。同时,设计合理的收益共享机制,使承运人在分散结构的运输系统中仍能实现运输链的协调。     

基于侧扫声纳的船舶吨位测量技术研究及应用

在自动化测量技术迅速发展的今天,国内外对船舶吨位的测定却主要依据船舶图纸及证件,存在着诸多弊端。为解决上述问题,本文在对侧扫声纳成像原理分析后,认为侧扫声纳对水面目标同样可以成像,设计了利用侧扫声纳测量内河航道过闸船舶实载总吨位的测量方案。为了对测量方案进行验证,本文使用Starfish 450F型侧扫声纳于常州魏村船闸开展实地测量实验,所得理论计算结果与实际丈量结果误差较小,证明了本文提出的船舶吨位测量技术的可行性,对船舶吨位自动化测量的实现具有一定的价值。     

Ethylene polymerization with novel bridged tri- and tetranuclear titanocene/MAO systems

Two benzene centered tri- and tetracyclopentadienyl ligands C₆H₃(CH₂C₅H₅)₃-1,3,5 (1) and C₆H₂(CH₂C₅H₅)₄-1,2,4,5 (2) and their titanium complexes C₆H₃[CH₂C₅H₄Ti(C₅H₅)Cl₂]₃-1,3,5 (3), C₆H₃[CH₂C₅H₄Ti(C₅H₄CH₃)Cl₂]₃-1,3,5 (4), as well as C₆H₂[CH₂C₅H₄Ti(C₅H₅)Cl₂]₄-1,2,4,5 (5) were synthesized and characterized by mass and ¹H NMR spectra. In the presence of methylaluminoxane (MAO), 3, 4 and 5 are efficient catalysts for ethylene polymerization in toluene. The influence of the polymerization conditions such as catalyst concentration, MAO/Ti molar ratio, polymerization time and temperature were investigated in detail. 3, 4 and 5 produce linear polyethylene (PE) with broad molecular weight distributions (MWD) and a little lower molecular weight.     

钱塘江通海航运开发及其导航问题

钱塘江通海航运开发对于浙江省的经济发展具有重要意义。根据该水域的地理特征,通海航运开发务必采取多学科的综合措施,其中建立导航定位系统并提高其精度是通海航运开发中的基础环节。应用国际上近十几年来迅速发展起来的无线电导航差分技术来提高导航定位精度,则是技术上可行、经济上合算的优化方案。本文对上述问题进行讨论,并结合作者于1987年夏在渤海海域进行我国首次无线电导航差分技术试验的经验,客观地评价了差分技术在钱塘江通海航运开发中应用的意义和前景以及存在的问题及其解决办法。     

Liner ship fleet deployment with week-dependent container shipment demand

This paper addresses a practical liner ship fleet deployment problem with week-dependent container shipment demand and transit time constraint, namely, maximum allowable transit time in container routing between a pair of ports. It first uses the space–time network approach to generate practical container routes subject to the transit time constraints. This paper proceeds to formulate the fleet deployment problem based on the practical container routes generated. In view of the intractability of the formulation, two relaxation models providing lower bounds are built: one requires known container shipment demand at the fleet deployment stage, and the other assumes constant container shipment demand over the planning horizon. An efficient global optimization algorithm is subsequently proposed. Extensive numerical experiments on the shipping data of a global liner shipping company demonstrate the applicability of the proposed model and algorithm.     

Ship routing and scheduling in the new millennium

We review research on ship routing and scheduling and related problems during the new millennium and provide four basic models in this domain. The volume of research in this area about doubles every decade as does the number of research outlets. We have found over a hundred new refereed papers on this topic during the last decade. Problems of wider scope have been addressed as well as more specialized ones. However, complex critical problems remain wide open and provide challenging opportunities for future research.