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Article
Publication date: 18 February 2019

Xiyi Yang and Tsz Leung Yip

This study aims to investigate the efficiency changes of 23 major Asian container ports for the period from 2000 to 2007. In addition to assess the general trend, it also…

Abstract

Purpose

This study aims to investigate the efficiency changes of 23 major Asian container ports for the period from 2000 to 2007. In addition to assess the general trend, it also attempts to decompose the overall efficiency change into technological efficiency change, technical efficiency change and scale efficiency change to help port authorities to devise operational strategies.

Design/methodology/approach

The Malmquist index method is used, which is derived from data envelopment analysis. In this model, technological improvement comes from using state-of-the-art technologies, technical improvement is from rationalizing of port inputs and scale efficiency is from adjustment of port operational scales.

Findings

On average, the investigated ports have improved their efficiencies by 14.3 per cent. Such efficiency gains can be attributed to a 41 per cent increase in pure technical efficiency, a 47.5 per cent increase in scale efficiency and a 30.5 per cent decrease in technological efficiency. The scale efficiency contributes the most to the overall efficiency improvement, while technical and technological effects seem to have less impact. The fact that technological efficiency has little variance seems to suggest that this source of efficiency gain may not bring substantial competitive advantage.

Research limitations/implications

The sample period is 2000-2007, so the impact from the Asian financial crisis or the economic downturn was not covered. Also, the port throughputs data do not separate shipment and transhipment.

Originality/value

This study provides valuable suggestions to improve efficiency for container ports along the “Maritime Silk Road.”

Details

Maritime Business Review, vol. 4 no. 1
Type: Research Article
ISSN: 2397-3757

Keywords

Article
Publication date: 29 August 2019

Wei Long, Mimi Wu, Fasha Li, Jiyao Wang and Wei Deng

The purpose of this paper is to develop the micro-electro-mechanical systems (MEMS) technology has created the conditions for the study of microfluidic technology…

Abstract

Purpose

The purpose of this paper is to develop the micro-electro-mechanical systems (MEMS) technology has created the conditions for the study of microfluidic technology. Microfluidic technology has become a very large branch in the MEMS field over the past decade. For aerostatic thrust bearing, the micro-fluidic gas flow in a small-scale gas film between two parallel plates is the subject of many studies. Because of the thin gas in the film, velocity slip occurs at the interface, which causes the gas flow pattern to change in the lubricating film. So, it is important to clarify the mechanism and pressure characteristics in thin firm gas flow.

Design/methodology/approach

First, a new assumption and corresponding models for the flow regime were established by theoretical analysis. Second, computational simulations about pressure distribution and velocity were given by a large-scale atomic/molecular massively parallel simulator (LAMMPS). Third, comparison of the results of LAMMPS simulation and direct simulation Monte Carlo calculation were made to verify the reliability of above results.

Findings

The gas flow mechanism and corresponding regulations are significantly different from traditional pneumo dynamics, which can be described by Navier–Stokes equations accurately. Combining theatrical study and computational results, the stratification theory of the gas film was verified. The research shows that when the gas flow rate increased, the pressure of the gas film decreased, the thickness of the continuous flow layer increased, the thickness of the thin layer decreased and the layered pressure in the gas film disappeared. In this case, velocity slippage could be ignored.

Originality/value

First, this paper established an analytical model of the gas film support and proposed a film stratification theory. The gas film was divided into the near wall layer, the thin layer and the continuous layer, which was proved by the calculation of LAMMPS flow simulation. The velocity slip boundary conditions theory is feasible. Second, the gas film size of the flat plate is at the micron level, which cannot be observed in its flow regimen, only determined by calculation and simulation. This paper proposes a new model and a new tool to analyze gas flow in gas films.

Details

Industrial Lubrication and Tribology, vol. 73 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

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