Dimos C. Charmpis and Manolis Papadrakakis
Balancing and dual domain decomposition methods (DDMs) comprise a family of efficient high performance solution approaches for a large number of problems in computational…
Abstract
Balancing and dual domain decomposition methods (DDMs) comprise a family of efficient high performance solution approaches for a large number of problems in computational mechanics. Such DDMs are used in practice on parallel computing environments with the number of generated subdomains being generally larger than the number of available processors. This paper presents an effective heuristic technique for organizing the subdomains into subdomain clusters, in order to assign each cluster to a processor. This task is handled by the proposed approach as a graph partitioning optimization problem using the publicly available software METIS. The objective of the optimization process is to minimize the communication requirements of the DDMs under the constraint of producing balanced processor workloads. This constraint optimization procedure for treating the subdomain cluster generation task leads to increased computational efficiencies for balancing and dual DDMs.
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Alexander Nock, Udechukwu Ojiako, Tolga Bektas and Max Chipulu
The way and manner in which energy is produced is known to have a significant impact on emissions. For this reason, the UK government has sought to enhance the efficiency of…
Abstract
Purpose
The way and manner in which energy is produced is known to have a significant impact on emissions. For this reason, the UK government has sought to enhance the efficiency of energy production/conversion by focusing on a number of energy production approaches, including Combined Heat and Power (CHP). The purpose of this paper is to describe a practical approach for assessing the feasibility of CHP.
Design/methodology/approach
The authors provide an overview of Combined Heat and Power (CHP); describe a new and easy‐to‐implement feasibility and optimisation model to aid in the installation of CHP; and discuss the practical feasibility issues of CHP through an analysis of existing case studies using the proposed model. The modelling utilises regression models which are created using historical data obtained from public sources.
Findings
Compared against alternatives, the model is shown to be particularly useful, as its functionality is embedded in resource‐intensive prime mover specifications obtained from seven real industrial cases.
Originality/value
The need for such a practical and easy‐to‐use model is driven by the existence of numerous models, which are mainly complex and not necessarily “user‐friendly”. The proposed model is set to provide a practical and user‐friendly model for CHP appraisal that is easy to understand and assess in terms of prime movers such as capital cost, payback, annual financial and CO2 savings.
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Alexander Nock, Udechukwu Ojiako, Tolga Bektas and Max Chipulu
This paper seeks to set out opportunities for the development of a UK‐focused feasibility and sizing model utilising linear programming.
Abstract
Purpose
This paper seeks to set out opportunities for the development of a UK‐focused feasibility and sizing model utilising linear programming.
Design/methodology/approach
Optimisation of the model is conducted using integer linear programming developed using Excel Solver.
Findings
When compared with comparable alternatives, the model is shown to be particularly useful as its functionality is embedded in resource intensive prime mover specifications obtained from seven real industrial cases.
Research limitations/implications
The study acknowledges the limitation of utilising sizing data primarily obtained from secondary sources to develop the model.
Originality/value
The practical usefulness of this model is that it has been built using “real”, as opposed to simulated‐data. When compared with comparable alternatives, the model is shown to be articularly useful as its functionality is embedded in resource intensive prime mover specifications obtained from seven real industrial cases.
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Iordanis Katemliadis and Andreas Papatheodorou
The tourism industry in Greece has come a long way since its beginning as a distinct economic activity to reach the recent impressive results. It is a sector that has grown…
Abstract
The tourism industry in Greece has come a long way since its beginning as a distinct economic activity to reach the recent impressive results. It is a sector that has grown remarkably and became a major source of growth for the Greek economy. As such this chapter aims to discuss the importance and the potential of the sector, the unique characteristics of the Greek tourism industry and the future challenges ahead. Tables and suitable graphics are provided to visually enhance and inform the discussion. A wide range of articles, journals, books, and electronic sources has been reviewed to present as accurately and up to date information as possible. This chapter can therefore prove useful for academics and non-academics to use it as a reference point for the tourism sector in Greece.
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S. Belesis and G. Labeas
The purpose of this paper is to present an efficient engineering methodology for solving the problem of non‐linear (NL) damage and post‐buckling of large‐scale structures, which…
Abstract
Purpose
The purpose of this paper is to present an efficient engineering methodology for solving the problem of non‐linear (NL) damage and post‐buckling of large‐scale structures, which is of high importance mainly for the aircraft industry.
Design/methodology/approach
The methodology takes advantage of the capabilities of finite element substructuring technique in the simulation of large/complex structures and exploits the advantages of local‐global analysis logic. The main innovation deals with the appropriate modification of superelement method, such that it can deal with NL behaviour and efficiently model the entire large‐scale structure. In this study, the proposed methodology is demonstrated in the treatment of geometrical non‐linearity and its efficiency is assessed in the case of a large‐scale fuselage section.
Findings
A method capable of solving large‐scale NL problems by taking advantage of the linear response of the different model regions is developed.
Research limitations/implications
Further development of the proposed method is required for handling other means of non‐linearity.
Originality/value
The proposed approach is advantageous in terms of computational effort over the corresponding conventional ones.