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Article
Publication date: 1 March 1986

G.L. VIVIANI and Y.A. SAET

An effective practical algorithm based on array oriented computations, suitable for use with vector computational architectures, is described. The algorithm allows for…

41

Abstract

An effective practical algorithm based on array oriented computations, suitable for use with vector computational architectures, is described. The algorithm allows for deteremination of self‐oscillations with unknown (in advance) periods, yet also includes the situation when the period is predetermined, particularly in the case of forced oscillations.

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COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 5 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 17 January 2018

Balachandar Pandiyan, Sivarajan Ganesan, Nadanasabapathy Jayakumar and Srikrishna Subramanian

The ever-stringent environmental regulations force power producers to produce electricity at the cheapest price and with minimum pollutant emission levels. The electrical power…

143

Abstract

Purpose

The ever-stringent environmental regulations force power producers to produce electricity at the cheapest price and with minimum pollutant emission levels. The electrical power generation from fossil fuel releases several contaminants into the air, and this becomes excrescent if the generating unit is fed by multiple fuel sources (MFSs). Inclusion of this issue in operational tasks is a welcome perspective. This paper aims to develop a multi-objective model comprising total fuel cost and pollutant emission.

Design/methodology/approach

The cost-effective and environmentally responsive power system operations in the presence of MFSs can be recognised as a multi-objective constrained optimisation problem with conflicting operational objectives. The complexity of the problem requires a suitable optimisation tool. Ant lion algorithm (ALA), the most recent nature-inspired algorithm, was used as the main optimisation tool because of its salient characteristics. The fuzzy decision-making mechanism has been integrated to determine the best compromised solution in the multi-objective framework.

Findings

This paper is the first to propose a more precise and practical operational model for studying a multi-fuel power dispatch scenario considering valve-point effects and CO2 emission. The modern meta-heuristic algorithm ALA is applied for the first time to address the economic operation of thermal power systems with multiple fuel options.

Practical implications

Power companies aim to make profit by abiding by the norms of the regulatory board. To achieve economic benefits, the power system must be analysed using an accurate operational model. The proposed model integrates total fuel cost, valve-point loadings and CO2 emission, which are prevailing power system operational objectives. The economic advantages of the operational model can be observed through economic deviation indices, and the performed analysis validates that the developed model corresponds to the actual power operation.

Originality/value

The realistic operational model is proposed by considering total fuel and pollutant emission, and the ALA is applied for the first time to address the proposed multi-objective problem. To validate the effectiveness of ALA, it is implemented in standard test systems with varying generating units (10-100) and the IEEE 30 bus system, and various kinds of power system operations are performed. Moreover, the comparison and performance analysis confirm that the current proposal is found enhanced in terms of solution quality.

Details

International Journal of Energy Sector Management, vol. 12 no. 1
Type: Research Article
ISSN: 1750-6220

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Article
Publication date: 3 May 2013

Gianpietro Granelli and Mario Montagna

The purpose of this work is that of providing the guidelines of an efficient implementation of power flow computations using the MATLAB computation environment.

1214

Abstract

Purpose

The purpose of this work is that of providing the guidelines of an efficient implementation of power flow computations using the MATLAB computation environment.

Design/methodology/approach

The goal of obtaining high efficiency from MATLAB programs often proves elusive unless special care is taken in exploiting the vectorising capability of MATLAB programming. In the present paper the implementation of Newton‐Raphson power flow in MATLAB is examined with particular emphasis on the way of obtaining a vectorisable code capable of achieving effective numerical performance by exploiting its formulation in terms of complex variables.

Findings

Tests on actual networks with up to 1,300 buses are presented. They show that the complex power flow is as efficient as the best implementations of the Newton Raphson power flow using real variables, as long as the operations involved are reordered with the aim of exploiting the vectorisation capabilities of the MATLAB environment.

Originality/value

It is shown that improved numerical efficiency in the MATLAB can be obtained through its formulation in terms of complex variables. The complex Newton‐Raphson load flow, not very common in practical uses, is shown to have many desirable qualities from the point of view of MATLAB programming and is presented in detail.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 3 January 2017

Natalia C. Rosca, Alin V. Rosca, John H. Merkin and Ioan Pop

The purpose of this study is to consider the effects that buoyancy arising from the combination of both thermal and concentration gradients can have on the mixed convection…

102

Abstract

Purpose

The purpose of this study is to consider the effects that buoyancy arising from the combination of both thermal and concentration gradients can have on the mixed convection boundary-layer flow near a forward stagnation point with the effect of Stefan blowing being included. Ad suitable choice for the functional forms of the outer flow and the wall temperature and concentration enables the problem to be reduced to a similarity form involving the dimensionless parameters, λ (mixed convection), κ (Stefan blowing) and N (relative strength of concentration driven buoyancy to that of thermal driven), as well as the Prandtl and Schmidt numbers. Numerical solutions to this similarity system for a range of representative parameter values indicate a finite, non-zero range of κ where there can be four solutions in opposing flow with only one solution in aiding flow. Asymptotic solutions for large values of N and κ are derived, the latter having two different structures in the opposing flow.

Design/methodology/approach

This paper sets up a similarity problem to examine the effects of Stefan blowing on a mixed convection flow with the aims of solving the equations numerically and complementing the results with appropriate asymptotic analysis.

Findings

The findings of the study include multiple solution branches, saddle-node bifurcations and singularities appearing in the solution.

Originality/value

The authors believe that all the results, both numerical and asymptotic, are original and have not been published elsewhere.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 27 no. 1
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 5 May 2015

Berta Schnettler, Horacio Miranda, German Lobos, Jose Sepulveda, Ligia Orellana, Marcos Mora and Klaus Grunert

The purpose of this paper is to explore differences in consumers’ willingness to purchase functional foods (FFs) in southern Chile in terms of socio-demographic characteristics…

1239

Abstract

Purpose

The purpose of this paper is to explore differences in consumers’ willingness to purchase functional foods (FFs) in southern Chile in terms of socio-demographic characteristics, consumer knowledge, and subjective well-being.

Design/methodology/approach

A survey was carried out among 400 people in southern Chile. The questionnaire measured willingness to buy FFs with 18 different benefits, knowledge about FFs, socio-demographic characteristics and satisfaction with life and with food-related life.

Findings

Two dimensions were found for benefits sought in FFs: disease prevention and improvement of bodily functions. Cluster analysis was used to distinguish three types of consumers. The majority (59.8 per cent) showed a significant disposition to buy FFs that prevent diseases or improve bodily functions. Others (25.8 per cent) were less inclined to buy either type of FF. A minority (14.5 per cent) showed greater disposition to buy FFs which improve bodily functions. The types differ according to the size of family, presence and age of children at home, ethnic origin, education, socio-economic status, knowledge about FFs and satisfaction with life and food-related life.

Research limitations/implications

This study was conducted in the context of only one country in South America. The results reveal a high interest to buy FFs in order to improve bodily functions, and this preference may be associated to lifestyle changes in the population in Latin American countries.

Originality/value

This study provides information on the willingness to buy FFs and relates it to ethnic origin and satisfaction with food-related life. People from ethnic minorities are less inclined to buy FFs. People who are more inclined to buy FFs are more satisfied with their life and their food-related life.

Details

British Food Journal, vol. 117 no. 5
Type: Research Article
ISSN: 0007-070X

Keywords

Available. Open Access. Open Access
Article
Publication date: 17 February 2023

Luca Pugi, Giulio Rosano, Riccardo Viviani, Leonardo Cabrucci and Luca Bocciolini

The purpose of this work is to optimize the monitoring of vibrations on dynamometric test rigs for railway brakes. This is a quite demanding application considering the continuous…

955

Abstract

Purpose

The purpose of this work is to optimize the monitoring of vibrations on dynamometric test rigs for railway brakes. This is a quite demanding application considering the continuous increase of performances of high-speed trains that involve higher testing specifications for brake pads and disks.

Design/methodology/approach

In this work, authors propose a mixed approach in which relatively simple finite element models are used to support the optimization of a diagnostic system that is used to monitor vibration levels and rotor-dynamical behavior of the machine. The model is calibrated with experimental data recorded on the same rig that must be identified and monitored. The whole process is optimized to not interfere with normal operations of the rig, using common inertial sensor and tools and are available as standard instrumentation for this kind of applications. So at the end all the calibration activities can be performed normally without interrupting the activities of the rig introducing additional costs due to system unavailability.

Findings

Proposed approach was able to identify in a very simple and fast way the vibrational behavior of the investigated rig, also giving precious information concerning the anisotropic behavior of supports and their damping. All these data are quite difficult to be found in technical literature because they are quite sensitive to assembly tolerances and to many other factors. Dynamometric test rigs are an important application widely diffused for both road and rail vehicles. Also proposed procedure can be easily extended and generalized to a wide value of machine with horizontal rotors.

Originality/value

Most of the studies in literature are referred to electrical motors or turbomachines operating with relatively slow transients and constant inertial properties. For investigated machines both these conditions are not verified, making the proposed application quite unusual and original with respect to current application. At the same time, there is a wide variety of special machines that are usually marginally covered by standard testing methodologies to which the proposed approach can be successfully extended.

Details

World Journal of Engineering, vol. 21 no. 3
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 25 October 2018

Karine Picot-Coupey, Jean-Laurent Viviani and Paul Amadieu

Why do some retail networks operate shop-in-shops along with stand-alone units while others do not? Drawing on a resource-based and intellectual capital (IC) perspective as a…

1290

Abstract

Purpose

Why do some retail networks operate shop-in-shops along with stand-alone units while others do not? Drawing on a resource-based and intellectual capital (IC) perspective as a broad theoretical lens, the purpose of this paper is to focus on retailer-run shop-in-shops and examine the determinants of their adoption.

Design/methodology/approach

To gain a comprehensive understanding of shop-in-shop adoption by retail branded networks, a research design mixing a quantitative study (n = 170) and a qualitative study (n = 19) was adopted to test nine hypotheses regarding these determinants of the adoption of retailer-run shop-in-shops and explore in greater depth the processes whereby they actually occur.

Findings

The main findings show that intangible resources are major determinants of the choice to operate shop-in-shops while tangible resources are minor determinants. The more robust results of the analysis lie in the positive effect of own-label merchandise range, premium pricing strategy, positioning based on symbols, retail concept fast renewal and high sector specialisation on the choice to operate a shop-in-shop. The effect of financial constraints on the decision to expand via shop-in-shops is limited.

Research limitations/implications

The authors emphasise the importance of marketing-related and company-related characteristics in differentiating the likelihood of retail networks to expand via shop-in-shops. These results lend support to the relevance of a resource-based and IC perspective in explaining the propensity of retailers to develop via shop-in-shops.

Practical implications

The decision to operate shop-in-shops should depend on the extent to which intangible resources – the most important being retail positioning grounded in symbols, an own-label merchandise range, and a high retail branded network reputation – can be valued and enhanced. Expanding a retail network via shop-in-shops does not appear to be a financially constrained expansion strategy: it must be considered as a relevant first best strategy when an independent and young retail company has intangible resources to value but limited tangible resources.

Originality/value

The study contributes to channel management and retailing research in four ways. First, it precisely delineates the specific characteristics of shop-in-shops. Second, it provides theoretical explanations – based on a resource and IC perspective – of determinants that influence the choice of shop-in-shops. Third, it empirically tests the influence of marketing-related and company-related characteristics when adopting shop-in-shops. Fourth, it provides insights into how adopting shop-in-shops. To the authors’ knowledge, the research is on the first to analyse theoretically and test the determinants for the choice of retailer-run shop-in-shops.

Details

International Journal of Retail & Distribution Management, vol. 46 no. 10
Type: Research Article
ISSN: 0959-0552

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Publication date: 21 October 2019

Yung-Jae Lee and Xiaotian Tina Zhang

Literature has numerous debates about the relation between emerging financial environmental, social, and governance (ESG) factors and financial performance with mixed results. The…

Abstract

Literature has numerous debates about the relation between emerging financial environmental, social, and governance (ESG) factors and financial performance with mixed results. The authors use a unique data set generated by big data analytics (from web-based data mining) for three environmental areas (water, land, and air) to test hypothesis in the extreme events (defined as those that are over/under ±2.58 multiplied by the standard deviation) have a high chance of predicting equity price movements within an window of −3/+10 days, respectively, prior to and after the event. The authors repeat the similar robustness study for a sample of 2018 and the results still holds. The authors interpret these findings to suggest that: (1) studies using continuously AI-generated data for ESG categories can have significant predictive power for extreme events; and (2) that such high correlations can be used to confirm the materiality of some ESG data. The authors conclude with noting limitation of this initial study, and present specific areas for future research.

Details

Disruptive Innovation in Business and Finance in the Digital World
Type: Book
ISBN: 978-1-78973-381-5

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Book part
Publication date: 19 July 2018

Patrick Kraus, Bernd Britzelmaier, Peter Stokes and Neil Moore

The overall goal of this chapter is to critique the purported business case for corporate social responsibility (CSR) and sustainability, which persists as a major contentious…

Abstract

Purpose

The overall goal of this chapter is to critique the purported business case for corporate social responsibility (CSR) and sustainability, which persists as a major contentious force in convincing companies to become more sustainable. Extant literature on sustainability, CSR and Socially Responsible Investments (SRIs) generally tends to focus on company perspectives decision-making and approaches. This chapter considers an alternative and under-developed perspective and examines CSR from a consumer/public perspective situated in a German context.

Design/methodology/approach

This chapter builds a comprehensive literature review and employs a research philosophical point of view underpinned by a social constructionist stance. It examines indicators and attitudes towards sustainability and sustainable consumption together with socially responsible investments and considers whether the buying patterns of German consumers may serve as a rationalisation for a potential business case for CSR and sustainability.

Findings

While the awareness of consumers of CSR in Germany towards sustainability tends to be generally relatively prima facie high, it is nevertheless noticeable that German consumers are predominately reluctant to pay a price premium for product possessing a superior sustainability performance. From the alternative lens of SRIs, rather than being a replete and widespread phenomenon, they are still largely a niche market. For these reasons, the potential for the existence of a business case for sustainability, CSR and SRIs tends in reality to be low, in spite of some populist or survey reports and perceptions.

Originality/value

The chapter links a consumer perspective with the business case for CSR. Moreover, it focuses on the German context which tends to be underrepresented in international research.

Details

The Critical State of Corporate Social Responsibility in Europe
Type: Book
ISBN: 978-1-78756-149-6

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Article
Publication date: 7 November 2019

Mariana Lima Scortegagna, Viviani Ruffo de Oliveira, Isadora Pasini, Medelin Silva, Alessandro de Oliveira Rios and Divair Doneda

Patients with phenylketonuria (PKU) require a phenylalanine (Phe)-restricted diet due to its toxic effects on such subjects. Considering the low availability of specific foods for…

220

Abstract

Purpose

Patients with phenylketonuria (PKU) require a phenylalanine (Phe)-restricted diet due to its toxic effects on such subjects. Considering the low availability of specific foods for these patients, the purpose of this paper is to make breads with low Phe content while also conducting physicochemical and sensory analysis of the samples.

Design/methodology/approach

Five bread formulations with a common base were prepared, in which manioc – Manihot esculenta (T1); Baroa potato – Arracacia xanthorrhiza (T2); sweet potatoes – Ipomoea batatas (T3); potatoes – Solanum tuberosum (T4); and, finally, yacon potato – Smallanthus sonchifolius (T5) were added.

Findings

The physical analysis showed that the samples had similar weight, height and size values, indicating that the use of different types of vegetables does not compromise the final result of the preparation. The chemical analysis showed that the loaves were low in protein and Phe and, therefore, are considered safe preparations for patients with PKU. In the sensory analysis, all the preparations presented satisfactory characteristics for consumption, specially the one with the addition of potato.

Research limitations/implications

The preparation of breads with low Phe content is a challenging task as it is necessary to exclude formulations with flours that present better technological performance. However, the results in this study showed that it is possible to get around the difficulties and obtain a viable product with easily purchased ingredients. It is known that sensory analysis with PKU patients as judges could have changed these results because their perception can differ from that of general population. The workgroup is continuing this study and we intend to take sensory analysis with PKU patients to future, as they have a pathology, the study needs special care and respectful ethical aspects.

Originality/value

PKU has a direct influence on the daily diet of the patient, interfering with life decisions that go form eating at their home to where and what to eat in environments out of their control. Therefore, creating specific preparations for such patients is a challenge that assists in adherence to dietary therapy.

Details

British Food Journal, vol. 122 no. 1
Type: Research Article
ISSN: 0007-070X

Keywords

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