Container storage and transshipment marine terminals

This study addresses the storage arrangement of transshipment containers on a container yard, in order to carry out efficiently the ship handling operations at a terminal where mega-containerships call. An optimization model is specified to investigate the flow of containers from the mega-containership to feeder ships using intermediate storage at the yard. A heuristic based on the lagrangian relaxation is formulated. The quality of the heuristic approach is tested in a number of experiments. In the experiments, various situations are analyzed with respect to mega-containership arrival rates, some strategies for stack arrangements and terminal layouts.     

Lease Maturity and Initial Rent: Is There a Term Structure for UK Commercial Property Leases?

Seminal work by Grenadier (J. Financ. Econ. 38:297–331, 1995) derived a set of hypotheses about the pricing of different lease lengths in different market conditions. Whilst there is a compelling theoretical case for and a strong intuitive expectation of differential pricing of different lease maturities, to date the empirical evidence is inconclusive. Drawing upon a substantial database of commercial lettings in central London (West End and City of London) over the last decade, we investigate the relationship between rent and lease maturity. In particular, we test whether building quality, credit risk and micro-location variables omitted in previous studies provide empirical results that are more consistent with the theoretical and intuitive a priori expectations. It is found that initial leases rates are upward sloping with the lease term and that this relationship is constant over time.

An inventory and order admission control policy for production systems with two customer classes

In this paper we examine a Markovian single-stage system producing a single item to satisfy demand of two different customer classes. A simple threshold type heuristic policy is proposed for the joint control of inventories and backorders. Explicit forms of the steady-state probabilities under this policy are derived and used to assess the average profit rate of the system and determine the optimal control parameters. Certain properties of the average profit rate are established and used to develop computationally efficient algorithms for finding the optimal control parameter values. Numerical results show that the proposed policy is a very good approximation of the optimal policy and outperforms other commonly used policies.     

The dynamics of crop sectors in regional development: The case of tobacco

The importance of specific crop sectors can be better cast in a broader framework to account for intersectoral effects. Input-output analysis can provide this framework to assess the importance of the controversial crop, tobacco. In this respect, employment, income, and output multipliers were estimated to demonstrate the dynamics of the sector at the regional and national levels. Furthermore, the impact of totally eliminating tobacco cultivation was computed. Results clearly demonstrate the significance of the tobacco sector and its interrelation with the rest of the economic sectors.This study was partially financed by the Portuguese Association of Tobacco Producers.     

The simultaneous berth and quay crane allocation problem

This paper addresses efficient berth and crane allocation scheduling at a multi-user container terminal. First, we introduce a formulation for the simultaneous berth and crane allocation problem. Next, by employing genetic algorithm we develop a heuristic to find an approximate solution for the problem. The fitness value of a chromosome is obtained by crane transfer scheduling across berths, which is determined by a maximum flow problem-based algorithm based on a berth allocation problem solution defined by the chromosome. The results of numerical experiments show that the proposed heuristic is applicable to solve this difficult but essential terminal operation problem.     

A multiplicative process for generating the rank-order distribution of UK election results

Human dynamics and sociophysics suggest statistical models that may explain and provide us with a better understanding of social phenomena. Here we propose a generative multiplicative decrease model that gives rise to a rank-order distribution and allows us to analyse the results of the last three UK parliamentary elections. We provide empirical evidence that the additive Weibull distribution, which can be generated from our model, is a close fit to the electoral data, offering a novel interpretation of the recent election results.     

Multi-port vs. Hub-and-Spoke port calls by containerships

This paper addresses the design of container liner shipping networks taking into consideration container management issues including empty container repositioning. We examine two typical service networks with different ship sizes: multi-port calling by conventional ship size and hub-and-spoke by mega-ship. The entire solution process is performed in two phases: the service network design and container distribution. A wide variety of numerical experiments are conducted for the Asia–Europe and Asia–North America trade lanes. In most scenarios the multi-port calling is superior in terms of total cost, while the hub-and-spoke is more advantageous in the European trade for a costly shipping company.     

Regional economic development and environmental repercussions: An environmental input-output approach

This study attempts to examine issues related to the existing adverse relationship between regional economic development and natural environment protection. For doing so, a regional environmental input-output model for the region of central Macedonia in northern Greece is constructed in order to quantify the direct and indirect undesirable negative effects of the production process in the natural environment. The results suggest that there is a considerable trade-off between economic development and environmental deterioration which should be taken into account when policy decisions are made. This paper benefitted from comments by the participants of the Forty-Seventh International Atlantic Economic Conference, Vienna, Austria, March 16–23, 1999.