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1 – 10 of over 5000
Article
Publication date: 14 May 2020

Liang Yang, Andrew Buchan, Dimitrios Pavlidis, Alan Jones, Paul Smith, Mikio Sakai and Christopher Pain

This paper aims to propose a three-phase interpenetrating continua model for the numerical simulation of water waves and porous structure interaction.

Abstract

Purpose

This paper aims to propose a three-phase interpenetrating continua model for the numerical simulation of water waves and porous structure interaction.

Design/methodology/approach

In contrast with one-fluid formulation or multi-component methods, each phase has its own characteristics, density, velocity, etc., and each point is occupied by all phases. First, the porous structure is modelled as a phase of continua with a penalty force adding on the momentum equation, so the conservation of mass is guaranteed without source terms. Second, the adaptive unstructured mesh modelling with P1DG-P1 elements is used here to decrease the total number of degree of freedom maintaining the same order of accuracy.

Findings

Several benchmark problems are used to validate the model, which includes the Darcy flow, classical collapse of water column and water column with a porous structure. The interpenetrating continua model is a suitable approach for water wave and porous structure interaction problem.

Originality/value

The interpenetrating continua model is first applied for the water wave and porous structure interaction problem. First, the structure is modelled as phase of non-viscous fluid with penalty force, so the break of the porous structure, porosity changes can be easily embedded for further complex studies. Second, the mass conservation of fluids is automatically satisfied without special treatment. Finally, adaptive anisotropic mesh in space is employed to reduce the computational cost.

Details

Engineering Computations, vol. 38 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 11 January 2016

Fei Du, Feng Yang, Liang Liang and Mingming Yang

This study aims to analyze the tradeoff between two potential marketing strategies for service providers, namely, market segmentation on the basis of reservation lead time…

2260

Abstract

Purpose

This study aims to analyze the tradeoff between two potential marketing strategies for service providers, namely, market segmentation on the basis of reservation lead time and cooperation with third parties.

Design/methodology/approach

This paper proposes an optimization model to describe market segmentation strategy after cooperating with third parties by taking hotels for example.

Findings

The results show that the profitability of adopting two strategies simultaneously is lower than that with market segmentation alone under some cases, which is relevant with attributes of travel agencies, such as switch rate and market share.

Research limitations/implications

This study indicates that cooperation with third parties has a negative impact on profitability of hotels using market segmentation in some cases. However, randomness of demand, customer loyalty and existence of cancellation should be considered in further research.

Practical implications

In an e-commerce era, hotels with market segmentation based on reservation lead time, are not required to cooperate with third parties under a number of situations (e.g. high switch rates and small market sizes of travel agencies). In addition, hotels should revise the segmentation strategy based on the change rate of potential demand of individual customers. Furthermore, hotels should enhance customer loyalty, strengthen cooperation with travel agencies that possess large market shares or small switch rates.

Originality/value

The study preliminarily formulates the optimal market segmentation strategy on the basis of reservation lead time after cooperating with third parties, which contributes to the revenue management.

Details

International Journal of Contemporary Hospitality Management, vol. 28 no. 1
Type: Research Article
ISSN: 0959-6119

Keywords

Book part
Publication date: 31 May 2016

Carlos Pestana Barros and Peter Wanke

This chapter analyses the efficiency of African airlines using a two-stage network DEA (Data Envelopment Analysis) model. Network DEA models usually take into account the…

Abstract

This chapter analyses the efficiency of African airlines using a two-stage network DEA (Data Envelopment Analysis) model. Network DEA models usually take into account the production process with intermediate inputs derived from the first stage and a second stage that departs from it. This fundamental feature enables one to view the airline production process as a carry-over activity. The analysis covers the 2010–2013 period. The relative efficiency ranks are presented and policy implications are derived.

Details

Airline Efficiency
Type: Book
ISBN: 978-1-78560-940-4

Keywords

Article
Publication date: 21 December 2021

Xiao-xiao Liu, Hui-hui Liu, Guo-liang Yang and Jiao-feng Pan

The high-quality development of the real estate industry is crucial to the transformation of China's economy. However, few studies apply the productivity to explore the…

Abstract

Purpose

The high-quality development of the real estate industry is crucial to the transformation of China's economy. However, few studies apply the productivity to explore the development path of the real estate industry in China. To fill this gap, this study mainly investigates the total factor productivity (TFP) of the real estate industry of 30 sample provinces in mainland China from 2007 to 2016.

Design/methodology/approach

The Malmquist index is applied to estimate the productivity (i.e. TFP) of the real estate industry, based on the data envelopment analysis (DEA). Then, the truncated tobit regression analysis explores the external influencing factors on the TFP of the real estate industry.

Findings

Through empirical analysis, it is found that the high-quality development of the real estate industry depends on the technological innovation by the real estate enterprises and the targeted policies by the provincial government. Moreover, the development of the real estate industry has a positive correlation with the growth of China's economy but a negative correlation with the development of other industries.

Practical implications

TFP mainly reveals the development status of the provincial real estate industry and identifies the driving force for exploring the high-quality development mode of the real estate sector. Furthermore, the fluctuation rule of TFP can be applied to predict the development trend of the real estate industry in the future.

Originality/value

As an application, this study measures the TFP of the Chinese real estate industry in different provinces and periods. The results have meaningful policy implications for policymakers regulating the real estate industry.

Details

Engineering, Construction and Architectural Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 1 March 1999

Shuichi Torii, Wen‐Jei Yang and Shinzaburo Umeda

A theoretical and experimental study is performed to investigate unsteady, two‐dimensional, incompressible fluid flow over both sides of a slot‐perforated flat surface…

Abstract

A theoretical and experimental study is performed to investigate unsteady, two‐dimensional, incompressible fluid flow over both sides of a slot‐perforated flat surface, which is placed in a two‐dimensional channel. The governing boundary‐layer equations are discretized by means of a finite‐difference technique to determine streamwise and transverse velocity components. The roles of both the Reynolds number and the ratio of the slot width, d, to the plate thickness, δ, on the velocity field are disclosed. It is found from the study that: (i) the flow pattern between two plates can be classified into four categories depending on a combination of Re and d/δ, (ii) at a small value of Re and/or d/δ, flow over the slot exhibits no timewise variation, (iii) when Re and d/δ exceed certain values, an alternate crossing of flow from one side of the plate to the other occurs across the slot, and (iv) a further increase in Re results in a complex flow both inside the slot and on the plate downstream of the slot. These results are confirmed by the flow visualization using ion‐exchange resins.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 9 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 3 February 2021

Abdul Rehman, Mohammad Hassan Shirani Bidabadi, Liang Yang, Zheng Yu, Chen Hao, Chi Zhang and Zhigang Yang

This study aims to optimise the effect of pre-oxidation on hot corrosion behaviour of Tribaloy T-900 at 900 °C in mixed Na2SO4 and K2SO4.

87

Abstract

Purpose

This study aims to optimise the effect of pre-oxidation on hot corrosion behaviour of Tribaloy T-900 at 900 °C in mixed Na2SO4 and K2SO4.

Design/methodology/approach

Prior to hot corrosion experiment, pre-oxidation treatments were carried in ambient air at 900 °C for 1, 5 and 10 h, respectively. The hot corrosion experiments were performed in a box type furnace at 900 °C. Both surfaces of specimens were brushed with saturated salt solution of 75 wt.% Na2SO4 + 25 wt.% K2SO4. After brushing, the salt-coated specimens were placed in electric stove to ensure drying of salt. After drying, presence of 3 mg/cm2 salt on specimen’s surface was ensured through weighting.

Findings

The 1-h pre-oxidation treatment prior to hot corrosion showed superior hot corrosion resistance against molten salt attack. An optimum pre-oxidation time of 1 h helped timely formation of protective Cr2O3 layer and inhibited the formation of less stable and porous surface oxides of Ni and Mo during hot corrosion.

Originality/value

Pre-oxidation effect on hot corrosion behaviour of refractory metal (such as Mo in investigated alloy) containing alloy has never been reported previously. Refractory metals oxide (e.g. MoO3) could transform the corrosion phenomena to catastrophic failure through acidic fluxing.

Details

Anti-Corrosion Methods and Materials, vol. 68 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 May 2000

Xinmin Dai, Amy H. Lau and Ji‐liang Yang

Explains why, following China‘s implementation of a market economy, public accounting firms were required to affiliate (hook‐up) with existing government or educational…

1391

Abstract

Explains why, following China‘s implementation of a market economy, public accounting firms were required to affiliate (hook‐up) with existing government or educational institutions until 1993 when partnerships and limited liability firms were also allowed. Describes the rules relating to independent accounting firms and changes which should foster their development but reports that, in fact, most firms are still affiliated. Discusses the reasons for this and the resulting problems, e.g. lack of competition and independence, low quality of service and increases in fraud, misrepresentation and under‐disclosure. Reveals that despite the 1995 exposure draft on eliminating the hooking‐up structure few de‐affiliations have taken place and identifies four problems which need solving if full de‐affiliation is to be achieved.

Details

Managerial Finance, vol. 26 no. 5
Type: Research Article
ISSN: 0307-4358

Keywords

Book part
Publication date: 12 January 2012

Ioannis N. Lagoudis

There is significant amount of literature tackling different issues related to the port industry. The present chapter focuses on a single business unit of seaports aiming…

Abstract

There is significant amount of literature tackling different issues related to the port industry. The present chapter focuses on a single business unit of seaports aiming at the documentation of works related to container terminals.

An effort to review, collect and present the majority of the works present in the last 30 years, between 1980 and 2010, has been made in order to picture the problems dealt and methods used by the authors in the specific research field. To facilitate the reader, studies have been grouped under five categories of addressed problems (productivity and competitiveness, yard and equipment utilization, equipment scheduling, berth planning, loading/unloading) and four modelling methodologies (mathematics and operations research, management and economics, simulation, stochastic modelling).

The analysis shows that most works focus on productivity and competitiveness issues followed by yard and equipment utilisation and equipment scheduling. In reference to the methodologies used managerial and economic approaches lead, followed by mathematics and operations research.

In reference to future research, two fields have been identified where there is scope of significant contribution by the academic community: container terminal security and container terminal supply chain integration.

The present chapter provides the framework for researchers in the field of port container terminals to picture the so far works in this research area and enables the identification of gaps at both research question and methodology level for further research.

Details

Maritime Logistics
Type: Book
ISBN: 978-1-78052-340-8

Keywords

Article
Publication date: 16 April 2018

Yao-yao Song, Hui-hui Liu, Xiao-xiao Liu and Guo-liang Yang

This paper aims to measure Chinese regional thermal industries’ evolution.

148

Abstract

Purpose

This paper aims to measure Chinese regional thermal industries’ evolution.

Design/methodology/approach

This paper uses data envelopment analysis (DEA) and global Malmquist–Luenberger productivity (GMLP) index.

Findings

The results reveal that the development of Chinese thermal power industry varies significantly in different regions, and it is highly correlated with the level of local economic development. Although the change of technical efficiency and scale efficiency had different impacts on different regions from year to year, the overall GMLP index change shows a close relationship with the contemporaneous frontier shift.

Practical implications

The results indicate that the Chinese Government should make efforts to promote its policy implementations and regulations in thermal industries so that the contemporaneous frontier will shift toward the global technology frontier with more desirable outputs and less undesirable outputs.

Originality/value

As an application, this study uses DEA and GMLP index to measure the productivity of Chinese thermal industries in 30 Chinese provinces from 2006 to 2013. The results have the meaningful policy implications for decision makers in charge of Chinese thermal industries.

Details

International Journal of Energy Sector Management, vol. 12 no. 2
Type: Research Article
ISSN: 1750-6220

Keywords

Open Access
Article
Publication date: 29 September 2022

Arshad Ahmad Khan, Sufyan Ullah Khan, Muhammad Abu Sufyan Ali, Aftab Khan, Yousaf Hayat and Jianchao Luo

The main aim of this study is to investigate the impact of climate change and water salinity on farmer’s income risk with future outlook mitigation. Salinity and climate…

Abstract

Purpose

The main aim of this study is to investigate the impact of climate change and water salinity on farmer’s income risk with future outlook mitigation. Salinity and climate change are a threat to agricultural productivity worldwide. However, the combined effects of climate change and salinity impacts on farmers' income are not well understood, particularly in developing countries.

Design/methodology/approach

The response-yield function and general maximum entropy methods were used to predict the impact of temperature, precipitation and salinity on crop yield. The target minimization of total absolute deviations (MOTAD)-positive mathematical programming model was used to simulate the impact of climate change and salinity on socioeconomic and environmental indicators. In the end, a multicriteria decision-making model was used, aiming at the selection of suitable climate scenarios.

Findings

The results revealed that precipitation shows a significantly decreasing trend, while temperature and groundwater salinity (EC) illustrate a significantly increasing trend. Climate change and EC negatively impact the farmer's income and water shadow prices. Maximum reduction in income and water shadow prices was observed for A2 scenario (−12.4% and 19.4%) during 2050. The environmental index was the most important, with priority of 43.4% compared to socioeconomic indicators. Subindex amount of water used was also significant in study area, with 28.1% priority. The technique for order preference by similarity to ideal solution ranking system found that B1 was the best climatic scenario for adopting climate change adaptation in the research region.

Originality/value

In this study, farmers' income threats were assessed with the aspects of different climate scenario (A1, A1B and B1) over the horizons of 2030, 2040 and 2050 and three different indicators (economic, social and environmental) in Northwestern region of Pakistan. Only in arid and semiarid regions has climate change raised temperature and reduced rainfall, which are preliminary symptoms of growing salinity.

Details

International Journal of Climate Change Strategies and Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1756-8692

Keywords

1 – 10 of over 5000