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Article
Publication date: 12 July 2011

M.K. Smail, L. Pichon, M. Olivas, F. Auzanneau and M. Lambert

Aging wiring in cars, aircraft, trains and other transportation means is identified as a critical security area. The purpose of this paper is to develop a new methodology…

Abstract

Purpose

Aging wiring in cars, aircraft, trains and other transportation means is identified as a critical security area. The purpose of this paper is to develop a new methodology for wire diagnosis allowing the detection, localization and characterization of the fault in wiring network.

Design/methodology/approach

The direct problem (propagation along the cables) is modelled by RLCG circuit parameters and the finite difference time domain method. This model provides a simple and accurate method to simulate time domain reflectometry (TDR) responses. Genetic algorithms are combined with this wire propagation model to solve the inverse problem and to deduce physical information's about defects from the reflectometry response.

Findings

The results show the applicability of an inverse procedure dedicated to TDR for the localization and characterization of defects in simple wires and faulty wiring networks. With experimental results, the paper demonstrates the accuracy which can be provided for wire diagnosis.

Practical implications

The work provides an efficient tool for the diagnosis of embedded wire networks.

Originality/value

In this paper, a new method is developed and applied to detect, characterize and localize the defects in wiring networks: an inverse procedure is introduced for wire diagnosis. The presented methodology is applied for complex network structures and with measurement data.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 5 March 2018

Hakim Sadou, Tarik Hacib, Hulusi Acikgoz, Yann Le-Bihan, Olivier Meyer and Mohamed Rachid Mekideche

The principle of microwave characterization of dielectric materials using open-ended coaxial line probe is to link the dielectric properties of the sample under test to…

Abstract

Purpose

The principle of microwave characterization of dielectric materials using open-ended coaxial line probe is to link the dielectric properties of the sample under test to the measurements of the probe admittance (Y(f) = G(f)+ jB(f )). The purpose of this paper is to develop an alternative inversion tool able to predict the evolution of the complex permittivity (ε = ε′ – jε″) on a broad band frequency (f from 1 MHz to 1.8 GHz).

Design/methodology/approach

The inverse problem is solved using adaptive network based fuzzy inference system (ANFIS) which needs the creation of a database for its learning. Unfortunately, train ANFIS using f, G and B as inputs has given unsatisfying results. Therefore, an inputs selection procedure is used to select the three optimal inputs from new inputs, created mathematically from original ones, using the Jang method.

Findings

Inversion results of measurements give, after training, in real time the complex permittivity of solid and liquid samples with a very good accuracy which prove the applicability of ANFIS to solve inverse problems in microwave characterization.

Originality/value

The originality of this paper consists on the use of ANFIS with input selection procedure based on the Jang method to solve the inverse problem where the three optimal inputs are selected from 26 new inputs created mathematically from original ones (f, G and B).

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 9 June 2020

Mohammed Messadi, Larbi Hadjout, Youcef Ouazir, Hakim Bensaidane, Noureddine Takorabet, Thierry Lubin and Smail Mezani

This paper aims to propose a new 3D electromagnetic model to compute translational motion eddy current in the conducting plate of a novel linear permanent magnet (PM…

Abstract

Purpose

This paper aims to propose a new 3D electromagnetic model to compute translational motion eddy current in the conducting plate of a novel linear permanent magnet (PM) induction heater. The movement of the plate in a DC magnetic field created by a PM inductor generates induced currents that are at the origin of a heating power by Joule effect. These topologies have strong magnetic end effects. The analytical model developed in this work takes into account the finite length extremity effects of the conducting plate and the reaction field because of induced currents.

Design/methodology/approach

The developed model is based on the combination of the sub-domain’s method and the image’s theory. First, the magnetic field expressions because of the PMs are obtained by solving the three-dimensional Maxwell equations by the method of separation of variables, using a magnetic scalar potential formulation and a magnetic field strength formulation. Then, the motional eddy currents are computed using the Ampere law, and the finite length extremity effects of the conducting plate are taken into account using the image’s method. To analyze the accuracy of the proposed model, the obtained results are compared to those obtained from 3D finite element model (FEM) and from experimental tests performed on a prototype.

Findings

The results show that the developed analytical model is very accurate, even for geometries where the edge effects are very strong. It allows directly taking into account the finite length extremity effects (the transverse edge effects) of the conducting plate and the reaction field because of induced currents without the need of any correction factor. The proposed model also presents an important reduction in computation time compared to 3D finite element simulation, allowing fast analysis of linear PM induction heater.

Practical implications

The proposed electromagnetic analytical model can be used as a quick and accurate design tool for translational motion PM induction heater devices.

Originality/value

A new 3D analytical electromagnetic model, to find the induced power in the conducting plate of a novel translational motion induction heater has been developed. The studied heating device has a finite length and a finite width, which create edge effects that are not easily considered in calculation. The novelty of the presented method is the accurate 3D analytical model, which allows finding the real power heating and real distribution of the induced currents in the conducting plate without the need to use correction factor. The proposed model also takes into account the reaction field because of induced currents. In addition, the developed model improves an important reduction in the computation time compared with 3D FEM simulation.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 39 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 29 April 2021

Heng-Yang Lu, Yi Zhang and Yuntao Du

Topic model has been widely applied to discover important information from a vast amount of unstructured data. Traditional long-text topic models such as Latent Dirichlet…

Abstract

Purpose

Topic model has been widely applied to discover important information from a vast amount of unstructured data. Traditional long-text topic models such as Latent Dirichlet Allocation may suffer from the sparsity problem when dealing with short texts, which mostly come from the Web. These models also exist the readability problem when displaying the discovered topics. The purpose of this paper is to propose a novel model called the Sense Unit based Phrase Topic Model (SenU-PTM) for both the sparsity and readability problems.

Design/methodology/approach

SenU-PTM is a novel phrase-based short-text topic model under a two-phase framework. The first phase introduces a phrase-generation algorithm by exploiting word embeddings, which aims to generate phrases with the original corpus. The second phase introduces a new concept of sense unit, which consists of a set of semantically similar tokens for modeling topics with token vectors generated in the first phase. Finally, SenU-PTM infers topics based on the above two phases.

Findings

Experimental results on two real-world and publicly available datasets show the effectiveness of SenU-PTM from the perspectives of topical quality and document characterization. It reveals that modeling topics on sense units can solve the sparsity of short texts and improve the readability of topics at the same time.

Originality/value

The originality of SenU-PTM lies in the new procedure of modeling topics on the proposed sense units with word embeddings for short-text topic discovery.

Details

Data Technologies and Applications, vol. 55 no. 5
Type: Research Article
ISSN: 2514-9288

Keywords

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Article
Publication date: 16 July 2020

Badr-El-Boudour Bidouche, Thierry Lubin and Smaïl Mezani

The purpose of this paper is to investigate the transient performance of an induction machine coupled with a magnetic gear for industrial applications with low speed and…

Abstract

Purpose

The purpose of this paper is to investigate the transient performance of an induction machine coupled with a magnetic gear for industrial applications with low speed and high torque requirements. This new solution increases mechanical reliability and does not require maintenance and lubrication. The main objective is to study the direct-on-line starting ability of the electrical machine and its stability regarding a sudden change for the load torque.

Design/methodology/approach

A nonlinear analytical model for the induction machine and the magnetic gear is first developed. The model is then linearized around an operating point to obtain the transfer function between the load angle and the electromagnetic torque from which an analytical expression for the mechanical resonant frequency is obtained.

Findings

It is shown that the direct on-line starting is possible, if the moment of inertia of the load is not greater than a maximum value. Moreover, it is demonstrated that this new system present inherent overload protection.

Originality/value

A new high-performance direct-on-line starting electrical machine is proposed to achieve high torque at low speed without mechanical gear to improve reliability and reduce maintenance.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 39 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 31 May 2021

Farid Terbouche, Ali Hamza and Smail Gabi

The purpose of this paper is the analysis of the dissipation of pore water pressures in the core of an earth dam, under the effect of water level fluctuations in the…

Abstract

Purpose

The purpose of this paper is the analysis of the dissipation of pore water pressures in the core of an earth dam, under the effect of water level fluctuations in the reservoir under operating conditions, taking into account the partial emptying and filling.

Design/methodology/approach

The Taksebt Dam, Tizi-Ouzou, Algeria was chosen as a case study, using a two-dimensional transient finite element numerical model. The GeoStudio calculation software is used through the SEEP/W. The latter takes into account the flow in the saturated and unsaturated zone, the formulation of SEEP/W allows the analysis of the dissipation of pore water pressures in the dyke. Starting from the maximum level of the reservoir, at least one cycle of partial emptying-filling was modelled over an eight-year operating period from 2011 to 2019. The input variables were the water level variation curve, material properties and boundary conditions.

Findings

It can be concluded that the numerical results obtained from the simulation model on the different points studied, namely, the pore water pressures are satisfactory as long as they are close to those recorded in the field by the pore pressure cells with an average error not exceeding 10% except for some measurements where the error is 20%. When the water level in the reservoir varies, the pore water pressures vary and their behaviour follows these fluctuations. Some points in the dam are affected by negative pore water pressures. No abnormal situations have been detected pore water pressures.

Originality/value

The numerical results of the simulation are analysed and validated against actual pore pressure cell measurements under operating conditions.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

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Article
Publication date: 11 April 2021

Lakhdar Bourabia, Cheikh Brahim Abed, Mahfoudh Cerdoun, Smail Khalfallah, Michaël Deligant, Sofiane Khelladi and Taha Chettibi

The purpose of this paper is the development of a new turbocharger compressor is a challenging task particularly when both wider operating range and higher efficiency are…

Abstract

Purpose

The purpose of this paper is the development of a new turbocharger compressor is a challenging task particularly when both wider operating range and higher efficiency are required. However, the cumbersome design effort and the inherent calculus burden can be significantly reduced by using appropriate design optimization approaches as an alternative to conventional design techniques.

Design/methodology/approach

This paper presents an optimization-based preliminary-design (OPD) approach based on a judicious coupling between evolutionary optimization techniques and a modified one-dimensional mean-line model. Two optimization strategies are considered. The first one is mono-objective and is solved using genetic algorithms. The second one is multi-objective and it is handled using the non-dominated sorting genetic algorithm-II. The proposed approach constitutes an automatic search process to select the geometrical parameters of the compressor, ensuring the most common requirements of the preliminary-design phase, with a minimum involvement of the designer.

Findings

The obtained numerical results demonstrate that the proposed tool can rapidly produce nearly optimal designs as an excellent basis for further refinement in the phase by using more complex analysis methods such as computational fluid dynamics and meta-modeling.

Originality/value

This paper outlines a new fast OBPD approach for centrifugal compressor turbochargers. The proposal adopts an inverse design method and consists of two main phases: a formulation phase and a solution phase. The complexity of the formulated problem is reduced by using a sensitivity analysis. The solution phase requires to link, in an automatic way, three processes, namely, optimization, design and analysis.

Details

Engineering Computations, vol. 38 no. 9
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 7 June 2019

Yufei Yan, Zuoliang Ye and Miao Sun

Nowadays, some online retailing platforms emerge to integrate transport capacity to provide standard distribution service for sellers. Such an integrated form of service…

Abstract

Purpose

Nowadays, some online retailing platforms emerge to integrate transport capacity to provide standard distribution service for sellers. Such an integrated form of service is defined as delivery alliance (DA). To have a better understanding of how to price the service, this study aims to fixate on the seller’s problems and builds a series of profit maximization models in accordance with the two-sided market pricing theory within a platform business model.

Design/methodology/approach

In the present study, some optimization models are built in the two-sided market type and the optimal solutions are found in a three-dimensional decision space. By using the basic model as the benchmark, some optimization problems of DA in realistic situations are discussed. Particularly, a power-law-distribution model is established to deal with the uncertainty in forecasting. Also, a price-sensitive model and a loss-aversion model are presented to describe the various reactions of sellers to charging modes. Finally, some combined situations are discussed and the strategies are compared under the mentioned models.

Findings

By selecting the basic model as the benchmark, the specific pricing strategies are found for each context to yield the optimal profits. The flexibility of pricing strategy in the basic model and rigid pricing strategies in extended models, are discussed. As a result, the guidelines for the online retailing platforms are developed on designing and pricing the DA service.

Research limitations/implications

First, it would be interesting to expand the pricing plan of the platform. For instance, menu pricing and quantity discount have not been considered, which are common in practice. The time discounting has also been ignored. If the time value were calculated, the contract fees would be more critical due to the earliest of collecting money. Finally, those joiners who have huge order sizes are crucial for the ecosystem indeed, but arouse no attention. While in reality, they may have more power to bargain with the platform. Thus, how the platform competition affects the pricing strategies needs future research.

Originality/value

The optimal pricing strategies under these models are analytically found out, and it is shown that the presented models result in the same scale of joiners and profits in optimization. This suggests that DA works well in various behavioral contexts. This also suggests that DA is a significant controller in service quality improvement. Then, the optimal pricing strategies are compared among all the models. During this, it is discovered that the realistic contexts might reduce the profit, whereas an appropriate pricing strategy can pull this back without loss of service quality.

Details

Nankai Business Review International, vol. 10 no. 3
Type: Research Article
ISSN: 2040-8749

Keywords

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Article
Publication date: 3 September 2019

Sofiane Rahmouni and Rachid Smail

The purpose of this paper is to achieve the national strategic agenda’s criteria that aim for accomplishing sustainable buildings by estimating the effects of energy…

Abstract

Purpose

The purpose of this paper is to achieve the national strategic agenda’s criteria that aim for accomplishing sustainable buildings by estimating the effects of energy efficiency measures in order to reduce energy consumption and CO2 emission.

Design/methodology/approach

A design approach has been developed based on simulation software and a modeled building. Therefore, a typical office building is considered for testing five efficiency measures in three climatic conditions in Algeria. This approach is conducted in two phases: first, the analysis of each measure’s effect is independently carried out in terms of cooling energy and heating energy intensities. Then, a combination of optimal measures for each climate zone is measured in terms of three sustainable indicators: final energy consumption, energy cost saving and CO2 emission.

Findings

The results reveal that a combination of optimal measures has a substantial impact on building energy saving and CO2 emission. This saving can rise to 41 and 31 percent in a hot and cold climate, respectively. Furthermore, it is concluded that obtaining higher building performance, different design alternatives should be adapted to the climate proprieties and the local construction materials must be applied.

Originality/value

This study is considered as an opportunity for achieving the national strategy, as it may contribute in improving office building performance and demonstrating a suitable tool to assist stakeholders in the decision making of most important parameters in the design stage for new or retrofit buildings.

Details

Smart and Sustainable Built Environment, vol. 9 no. 3
Type: Research Article
ISSN: 2046-6099

Keywords

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Book part
Publication date: 27 December 2018

Abstract

Details

Perspectives on Diverse Student Identities in Higher Education: International Perspectives on Equity and Inclusion
Type: Book
ISBN: 978-1-78756-053-6

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