bluuebunny/crossref_metadata_2025 huggingface dataset:
Does repetition impair auditors' judgments?
Authors: Green Wendy
Published: September 2008

Purpose

The purpose of this paper is to examine whether the repetition effect bias noted in prior psychology literature impacts auditor judgments. Were auditors to succumb to this bias, repeated statements would be perceived to have higher validity than single exposure to the same statement, potentially impairing subsequent judgments, including audit opinions and thereby undermining audit quality.

Design/methodology/approach

Multiple explanatory hypotheses, including repeated explanations, were evaluated by audit seniors in an experimental analytical procedures setting where the nature (error or non‐error) and number (six or ten) of explanations was varied.

Findings

Auditors were not found to exhibit a repetition effect (measured as an absolute increase in perceived validity) however differences did occur in their judgments owing to both the nature and number of explanations considered. Consistently the likelihood for repeated items on short lists was increased and on longer it was decreased, while for non‐errors it was increased and for errors it was decreased.

Practical implications

These results suggest that audit quality could be impaired if auditors do not consider a broad set of plausible explanations, particularly where they receive repeated non‐error explanations.

Originality/value

No prior study has addressed this issue in this context.
Corporate governance, transparency and performance of Malaysian companies
Authors: Hassan Che Haat Mohd , Abdul Rahman Rashidah , Mahenthiran Sakthi
Published: September 2008

Purpose

The paper aims to examine the effect of good corporate governance practices on corporate transparency and performance of Malaysian listed companies.

Design/methodology/approach

Samples were selected using matched‐sampling method and hierarchical regression was employed to test the relationship between among corporate governance mechanism, transparency and performance.

Findings

Corporate governance factors have a strong predicting power on company performance, mainly due to debt monitoring and foreign ownership. However, there is a significant negative relation between audit quality and performance. The results find that performance is not associated with the level of disclosure and timely reporting. The results indicate that disclosure and timeliness are not significant contributing factors in the relationship between corporate governance and market performance.

Research limitations/implications

The data covers a one‐year period of 2002 only. This paper deals only with “one‐way” causality running from corporate governance mechanisms to performance, even though, there is evidence of “reverse‐way” and “two‐way” causality in governance literature.

Practical implications

This paper indicates that internal governance mechanisms are not important determinants to corporate performance. However, governance in forms of debt monitoring and foreign ownership have significant influence on corporate performance. Transparency (i.e. disclosure and timeliness of reporting) is not a significant mediating variable between corporate governance and performance.

Originality/value

Distinct from previous empirical research as the disclosure level is measured using self‐designed corporate governance index. Apart from a study conducted in an Asian setting of Malaysia, the study also tests transparency as a mediating variable between corporate governance and performance
Continuous online auditing as a response to the Sarbanes‐Oxley Act
Authors: El‐Masry El‐Hussein E. , Reck Jacqueline L.
Published: September 2008

Purpose

The purpose of this paper is to examine investors' perceptions of the usefulness of continuous online auditing (COA) prior to and after the Sarbanes‐Oxley (SOX) Act and assesses the current value relevance of continuous auditing. The paper examines two research questions: first, whether continuous online audits significantly impact investors' perceptions of firm risk and, consequently, the value of a firm and second, whether continuous online audits have a greater impact on investor assessment of a firm's risk subsequent to SOX.

Design/methodology/approach

A 2 × 2×2 × 2 between participants laboratory experiment was conducted. Technology risk was manipulated at (e‐commerce risks versus no e‐commerce risks), traditional financial risk was manipulated at (high financial leverage versus low financial leverage), COA was manipulated at (traditional annual audit versus continuous online audits), and pre‐ and post‐SOX was tested (2002 sample versus 2005 sample). The primary dependent variables used were investors' assessment of firm risk and investors' assessment of earnings per share estimates. Additionally, investors' confidence in their investing decision was captured.

Findings

Results indicate a demand for COA as reflected in investors' reduced firm risk estimates, and increased confidence in estimates. Comparative results from the 2005 sample and the 2002 sample indicate that the value relevance of COA has increased after the introduction of SOX in July 2002. We attribute this shift to investors' perception that COA is a factor that helps mitigate firm risk and relatedly boosts investor confidence in their investing decisions.

Research limitations/implications

Only a single proxy for traditional business risk (financial leverage) is examined. Future studies need to examine the ability of continuous online audits to mitigate other types of traditional business risks.

Originality/value

The study establishes the current economic feasibility of continuous online audits. Additionally, the most insightful finding of the study is that the value relevance of COA has increased after the introduction of SOX. This shift is due to investors' perceptions of COA as a factor that mitigates firm risk and helps boost confidence in their investing decisions. Implications for the profession, the classroom and public policy are discussed.
The effect of IT controls on financial reporting
Authors: Grant Gerry H. , Miller Karen C. , Alali Fatima
Published: September 2008

Purpose

The purpose of this paper is to examine information technology (IT) control deficiencies and their affect on financial reporting.

Design/methodology/approach

This study examines 278 companies reporting IT control deficiencies in the first three years of the SOX 404 requirements (2004‐2006). Using quantitative analysis, the study evaluates the impact of IT deficiencies on financial reporting and determines significant differences between companies that report IT deficiencies and companies that do not report IT deficiencies.

Findings

Four accounting errors: revenue recognition issues; receivables, investments and cash issues; inventory, vendor and cost of sales issues; and financial statement, footnote, US GAAP, and segment disclosures issues stand out as common financial reporting problems in companies reporting weak IT controls. This study also suggests that companies with IT control deficiencies report more internal control (IC) deficiencies, are smaller, pay higher audit fees, and are typically audited by smaller accounting firms.

Research limitations/implications

This research is limited in scope since only SOX accelerated filers are included in the analysis. As of this study, smaller, non‐accelerated filers are not required to report IC control weaknesses under SOX.

Originality/value

As of this research, no analysis exists to support or refute the relationship of IT controls and accounting errors. This study re‐affirms the widespread impact that deficient IT controls can have on the overall IC structure of the business. Our study reveals some of the important issues associated with IT in the financial reporting process. The role of IT in financial reporting systems is destined to escalate. Studies, like ours, can help managers and auditors identify IT problems that affect financial reporting and take remedial steps to correct these weaknesses.
The impact of harmonisation by the International Federation of Accountants
Authors: Fakhfakh Hamadi , Fakhfakh Mondher , Consuelo Pucheta‐Martínez María
Published: September 2008

Purpose

The purpose of this paper is to examine the impact of the new, revised International Standard on Auditing (Revised ISA700) in terms of the wording characteristics of Tunisian auditors' reports.

Design/methodology/approach

Measurement of the compliance of auditors' reports issued by Tunisian auditors with the new revised International Standard on Auditing (Revised ISA700).

Findings

It was found that the audit reports examined are not fully compliant with all the elements enumerated by the new standard issued by the International Federation of Accountants (IFAC).

Originality/value

This paper provides new empirical evidence about the level of compliance with the revised ISA700. It discusses the limits on standardisation efforts for national auditors' reports, and the implications for accounting firms and their audit clients.
Anonymity of library users in The Netherlands and Croatia
Authors: Schepman Tessie , Koren Marian , Horvat Aleksandra , Kurtovic Dejana , Hebrang Grgic Ivana
Published: September 2008

Purpose

The purpose of this paper is to document a joint research project aimed at investigating the existing library practices regarding protection of personal data, in view of computerization of libraries and its consequences, and awareness of the privacy (anonymity) of the library users that was carried out simultaneously in The Netherlands and Croatia in the autumn of 2007.

Design/methodology/approach

The research was a continuation of an ongoing cooperation between The Netherlands Public Library Association and the Department of Information Sciences, University of Zagreb. A questionnaire was developed based on previously conducted interviews with librarians and survey of recent literature on anonymity. It was carried out online via a special link on the web site of The Netherlands Public Library Association and sent by e‐mail to selected libraries in Croatia.

Findings

Replies obtained from 65 Dutch and 33 Croatian libraries of all types have been compared and commented in the paper. The research shows that despite existing differences in library facilities librarians in both countries have not yet become fully aware of all aspects of privacy issues that new services provided by the new technology have brought about, nor received adequate training or taken appropriate measures.

Research limitations/implications

Further research on library practices regarding data protection and measures and steps to be taken by libraries in order to improve the present inadequacies can be envisaged in future.

Originality/value

The paper provides information on data security issues in Dutch and Croatian libraries.
Once upon a time in Zimbabwe
Authors: Sapp Nelson Megan
Published: September 2008

Purpose

The purpose of this paper is to create a parallel timeline between the Zimbabwe Librarian, the national trade journal for librarianship during the 1970s, 1980s, and 1990s, government statistics, non‐governmental information, media reports, and other secondary sources to determine the effects of Zimbabwe's political and economic fortunes on libraries.

Design/methodology/approach

The primary methodology is a review of secondary sources in the form of trade journals, economic data and media reports. The approach of the paper is to compare the state of libraries in Zimbabwe during the 1970s, 1980s, 1990s, and 2005, showing the change in librarianship and library services as economic prosperity changed dramatically.

Findings

The policies of three successive governments have promised support for libraries but have ultimately been unable to implement a national library system. Libraries in 2008 have fewer resources available than they had in the 1960s.

Research limitations/implications

This paper is based on media sources as well as statistical data. The Zimbabwe Librarian ceased as a quarterly journal in approximately 1997. Since 2000, it has been issued as a semi‐annual journal. The author had access to a limited span of the Zimbabwe Librarian; therefore, this article focuses on the period from 1969‐1995. Media sources available in Zimbabwe after 2001 are frequently propaganda organizations.

Originality/value

This article provides an overview of historical and current events in the Zimbabwe library community in the light of political and economic events.
Traditional use patterns?
Authors: Ole Pors Niels
Published: September 2008

Purpose

The purpose of this paper is to present the main findings of a nation‐wide survey of Danish high school students and their use of libraries and digital resources. The presentation of the main findings includes different organisations of the data in clusters and user types. This organisation and analysis gives indications of the factors that influence the high school students' use of libraries and digital resources and it also explains the preferences and expectations the students have.

Design/methodology/approach

The study was conducted as a nation‐wide online survey to a sample of high schools in Denmark. The data collection was conducted in several steps. A sample of high schools was selected and asked if they would accept the opportunity to participate in the study. If they agreed, the director or a person appointed by the director selected two to three classes of students. The students received a link to the online questionnaire and completed it during a class hour. The result was 998 usable and valid responses. There was no way to secure a true random sample, but the sample is very much like the student population as it is registered in statistical yearbooks in relation to characteristics such as type of high school, gender and geographical distribution.

Findings

The findings indicate that traditional demographic factors alone cannot explain all of the variability in the students' information behaviour. Type of high school, gender and study year influence the use of libraries and digital resources but it also becomes clear that perceptions of the study and study preferences influence the information behaviour. It is also indicated that a correlation exists between the amount of use of libraries and digital resources. Further, it is indicated that high school students possess a rather traditional view of the importance of the different services and facilities offered by libraries.

Research limitations/implications

The limitations of the research are inherent in the methodology. First of all, one only gets answers in relation to the stated questions and statements. This implies that the students' use of other information grounds, horizons, social technologies are omitted from the study. It is probably valid to argue that the data collection methods bias the results in a “conservative” way.

Originality/value

The research is the first nationwide investigation into different aspects of high school students' use of libraries and information resources in Denmark.
Creating the next generation of library leaders
Authors: Arnold Jennifer , Nickel Lisa T. , Williams Lisa
Published: September 2008

Purpose

The paper aims to answer the question: “Where is our profession going and who is leading us there?”

Design/methodology/approach

The article presents results of a survey directed to leadership institute attendees and attempts to determine the impact of such institutes on librarians' careers, and their willingness to move into administrative positions (department head, director, etc.) or leadership roles (project leader, committee chair). This paper was developed from the poster session, “Follow Me! Are Leadership Institutes Creating the Next Generation of Library Leaders?” presented at the American Library Association's Annual Conference in Washington, DC, June 24, 2007. Survey questions allowed data collection on the nature and impact of the leadership institute experience, attendees' supervisory and administrative experience, and their future professional goals. The role of leadership mentors and the potential of mentorship to increase the number of library leaders was also considered.

Findings

Librarians who attended leadership institutes felt it had a direct impact on their careers because they are more willing to move into leadership, management, and administrative roles. The majority of attendees find their leadership institute experience professionally valuable and would recommend it to others. Additionally, survey findings reveal the importance of professional mentors.

Research limitations/implications

The survey was limited to librarians who attended a leadership institute. Approximately 75 percent of respondents were female, with only 25 percent male, which reflects the general demographics of the profession as a whole.

Practical implications

Leadership institutes should be developed to focus on particular constituencies. A variety of formats – retreats, year‐long – will also help address different needs among potential attendees. Current library and institutional administrators should encourage librarians to develop their leadership potential.

Originality/value

This paper addresses the insufficient number of librarians both willing and prepared to take on leadership roles both within individual libraries and the profession at large, which is a growing concern to the library profession.
Library cooperation the Polish way: toward NUKAT and WorldCat in Poland
Authors: Hollender Henryk , Kasprzyk Agnieszka
Published: September 2008

Purpose

The purpose of this paper is to discuss the development of library catalogs and the national union catalog in Poland and the inclusion of the latter in OCLC's WorldCat, bringing Polish cultural life from authors to researchers and composers to a worldwide audience.

Design/methodology/approach

Two Polish librarians deeply involved in the liaison with OCLC over WorldCat discuss the development of library automation and catalogs in the country, in particular NUKAT, the national union catalog for academic and research libraries in Poland. The article also covers the inclusion of Polish library data in Google Scholar.

Findings

There is a wealth of Polish content now available via WorldCat – currently around 900,000 items are available.

Practical implications

Makes researchers aware of data on Polish publications that can now be found via OCLC's WorldCat and Google Scholar. Poland is one of Europe's major publishing countries, with around five per cent of Europe's publications a year.

Originality/value

Provides an overview of the cataloguing situation in one of Eastern Europe's more recent member states of the European Union.
The current status and challenges of collaboration in library and information studies (LIS) education and training in Africa
Authors: Ocholla Dennis N.
Published: September 2008

Purpose

The purpose of this paper is to discuss the current status and challenges of collaboration in library and information education and training in Africa.

Design/methodology/approach

The paper largely draws examples from experiential knowledge and observation; basic bibliometric analysis; and studying related institutional documents as well as African studies in the domain.

Findings

Most of the library and information studies (LIS) schools are based in Anglophone Africa and located within universities. Common trends of LIS education are shared by most LIS schools in Africa. Major challenges facing LIS education include the regulation of student numbers, knowledge and diversification of LIS job markets, funding of LIS schools, the development of technology infrastructures both in quantity and quality, allowing efficient access and the continued development of education through short courses that provide new knowledge, skills and attitudes to LIS workers. Collaboration of LIS schools in the region is weak and largely informal. There is hardly any research collaboration amongst LIS schools in Africa.

Research limitations/implications

Opportunities for collaboration that exist require initiatives, involvement and leadership. Organizing LIS schools workshops and pre/post conferences during national, regional and international conferences is an excellent way to begin unravelling a considerable portion of the current collaborative plight by engaging relevant stakeholders.

Originality/value

The paper raises primary challenges and opportunities for collaboration in LIS education and training in Africa thereby providing useful, current information that should inform LIS educators, researchers, students and other stakeholders on the status and challenges of collaboration in LIS education on the continent.
Succession planning in libraries
Authors: Topper Elisa F.
Published: September 2008

Purpose

This article aims to draw attention to the fact that succession planning is crucial to libraries.

Design/methodology/approach

The article is a literature review and commentary on the topic of succession planning in libraries.

Findings

Libraries need to make succession planning a priority of human resource management.

Originality/value

The value of planning ahead is needed with the exodus of baby boomers.
Report from the 2008 BOBCATSSS symposium in Zadar, Croatia
Authors: Tallerås Kim
Published: September 2008

Purpose

The purpose of this paper is to provide a flavour of the content of the BOBCATSSS Symposium, held in Zadar, Croatia, in January 2008.

Design/methodology/approach

A brief and subjective account of approaches to the main topics of this conference is the approach taken in the article.

Findings

The theme of the symposium, “Access to information for everyone” invited a variety of approaches that show the complexity regarding the future library institution and the future roles of the librarian. The conference included areas such as technological developments, e.g. Web 2.0 and e‐inclusion, digital rights management, open access, and the library as physical space.

Originality/value

A brief report of value to library and information professionals regarding provision of access to information and the future of libraries and librarians.
Concentrated winding PM machines: a pre‐design approach
Authors: Abdennadher Imen , Masmoudi Ahmed , Elantably Ahmed
Published: September 2008

Purpose

The purpose of this paper is to discuss the design of concentrated winding permanent magnet (PM) machines dedicated to propulsion applications considering both surface‐mounted and flux‐concentrating arrangements of the PMs.

Design/methodology/approach

Following the selection of a suitable distribution of the concentrated winding, a derivation of the machine inductances is carried out in order to highlight the increase in the flux‐weakening range gained through the substitution of distributed windings by concentrated ones. Then, mmf and finite element analysis are carried out in order to investigate the air gap flux density and the torque production capability of both surface‐mounted and flux‐concentrating PM machines.

Findings

The paper finds that, although both machines provide almost the same average torque, the surface‐mounted PM machine offers lower torque ripple with respect to the flux‐concentrating arrangement: a crucial benefit in electric and hybrid propulsion systems.

Research limitations/implications

The research should be extended to the comparison of the obtained results related to the torque production capability with experimental measurements.

Practical implications

An increase in the efficiency associated with the extension of the flux‐weakening range and a reduction of the volume make the concentrated winding PM machines interesting candidates, especially in large‐scale production applications such as the automotive industry.

Originality/value

The paper proposes an approach to design and performance investigation of concentrated winding PM machines considering both surface‐mounted and flux‐concentrating arrangements of the PMs.
Magnetic equivalent circuit model of a hybrid excitation synchronous machine
Authors: Hlioui S. , Vido L. , Amara Y. , Gabsi M. , Miraoui A. , Lécrivain M.
Published: September 2008

Purpose

The purpose of this paper is to present an analytical modeling based on lumped parameter magnetic circuits of a hybrid excitation synchronous machine. The model is first established and compared with 3D finite elements analysis and measurements. It is then used to optimise hybrid excitation effectiveness.

Design/methodology/approach

The machine studied, which has a 3D structure, requires the use of 3D finite elements method. The 3D FEA tool is still time‐consuming, which limits its use in optimal design process. To overcome this limitation the paper investigates an analytical modeling based on lumped parameter magnetic circuits. The developed model is then used in an optimisation procedure.

Findings

The machine presented has an original structure. It has been subject to a patent protection. The operating principle of this structure has been presented and optimisation of hybrid excitation effectiveness has been investigated. Double excitation allows one to control air gap flux while reducing permanent magnets' demagnetisation risk.

Originality/value

The paper presents an original structure with true field regulation capability. The principle of operation has been presented. A prototype has been built and tested. The paper also presents a 3D finite elements analysis of this machine and an analytical modelling.
Reluctant network‐based investigation of a claw pole alternator with DC excitation in the stator
Authors: Aloui Helmi , Ibala Amina , Masmoudi Ahmed , Gabsi Mohamed , Lécrivain Michel
Published: September 2008

Purpose

The purpose of this paper is to propose improvement of the generation capability of a claw pole alternator with DC excitation in the stator (CPAES) using analytical investigation based on a dedicated reluctant model.

Design/methodology/approach

The paper analyzes the effects of geometry and material transformations of the magnetic circuit on the generation capability of the CPAES as well as the reduction of claw‐claw leakage flux by inserting permanent magnets in between adjacent claws.

Findings

The generation capability could be improved considering the proposed geometry and material changes of the magnetic circuit of the CPAES. The inclusion of permanent magnets in between adjacent claws offers an increase of the alternator generation due to the reduction of the claw‐claw leakage flux.

Research limitations/implications

The research should be extended by building a new prototype of the CPAES in order to compare analytical results and experimental ones.

Practical implications

A new concept with no brush‐ring for excitation and an improvement of the generation capability of the alternator make the CPAES an interesting candidate especially in large‐scale production applications such as the automotive industry.

Originality/value

The paper proposes a new alternator topology called claw pole alternator with DC excitation in the stator (CPAES) and an analytical approach to improve the generation capability of such a concept, which represents a crucial challenge in electric generation systems especially in automotive applications.
Acoustic noise of electromagnetic origin in a fractional‐slot induction machine
Authors: Le Besnerais Jean , Lanfranchi Vincent , Hecquet Michel , Brochet Pascal , Friedrich Guy
Published: September 2008

Purpose

The purpose of this paper is to apply a fast analytical model of the acoustic behaviour of pulse‐width modulation (PWM) controlled induction machines to a fractional‐slot winding machine, and to analytically clarify the interaction between space harmonics and time harmonics in audible electromagnetic noise spectrum.

Design/methodology/approach

A multilayer single‐phase equivalent circuit calculates the stator and rotor currents. Air‐gap radial flux density, which is supposed to be the only source of acoustic noise, is then computed with winding functions formalism. Mechanical and acoustic models are based on a 2D ring stator model. A method to analytically derive the orders and frequencies of most important vibration lines is detailed. The results are totally independent of the supply strategy and winding type of the machine. Some variable‐speed simulations and tests are run on a 700 W fractional‐slot induction machine in sinusoidal case as a first validation of theoretical results.

Findings

The influence of both winding space harmonics and PWM time harmonics on noise spectrum is exposed. Most dangerous orders and frequencies expressions are demonstrated in sinusoidal and PWM cases. For traditional integral windings, it is shown that vibration orders are necessarily even. When the stator slot number is not even, which is the case for fractional windings, some odd order deflections appear: the radial electromagnetic power can therefore dissipate as vibrations through all stator deformation modes, leading to a potentially lower noise level at resonance.

Research limitations/implications

The analytical research does not consider saturation and eccentricity harmonics which can play a significant role in noise radiation.

Practical implications

The analytical model and theoretical results presented help in designing low‐noise induction machines, and diagnosing noise or vibration problems.

Originality/value

The paper details a fully analytical acoustic and electromagnetic model of a PWM fed induction machine, and demonstrate the theoretical expression of main noise spectrum lines combining both time and space harmonics. For the first time, a direct comparison between simulated and experimental vibration spectra is made.
Acoustic noise emitted by passive components in magnetic devices and design of a low‐noise industrial inductor
Authors: Barre Olivier , Napame Bellemain , Hecquet Michel , Brochet Pascal
Published: September 2008

Purpose

The purpose of this paper is to present the original study of an industrial device. Industrial inductors are used to decrease the current variations, resulting from the use of modern power converters. To reduce these variations, the magnetic energy stored in these components is automatically used when the receptor is unconnected to the principal sources. Such storage is generally obtained by using a magnetic circuit containing air‐gaps. The rigidity of this circuit, associated with the magnetic stresses which appear in these areas, causes the structure to produce mechanical vibration and to emit audible sounds.

Design/methodology/approach

Experiments, simulations and test devices are used to determine the main physical phenomenon that generates the undesirable audible noise. The resulting knowledge is used to design a quieter device.

Findings

The mechanical vibrations and emitted noises are attached to magnetic effects. Even if it is not possible to suppress all these effects, the level of sound emitted can be decreased through a suitable design of the magnetic core.

Originality/value

Industrial inductors are usually built and designed using methods coming from the transformer studies. A new concept for the design of the magnetic core is presented. Experimental approaches and numerical simulations are performed in order to highlight the physical behaviours of the coils and their magnetic coupling to the magnetic core. It appears that breaking the magnetic core into free parts is an original solution that decreases the emitted noise.
A microcontroller‐based soft‐starter for residential air‐conditioners: harmonic analysis
Authors: El Ferik S. , Ahmed C.B. , Ben Amor L. , Hussain S.A.
Published: September 2008

Purpose

The purpose of this paper is to reduce the inrush current and dip in voltage for energy‐ saving purposes in relation to residential air‐conditioning systems.

Design/methodology/approach

The paper focuses on the experimental harmonic investigation of a window‐type residential AC unit line current under time‐based soft‐starting control strategy. The control strategy assumes that only source voltage and current measurements are available. The soft‐starter is based on power electronic devices controlled through a firing signal generated by a programmed microcontroller during the first 500 ms.

Findings

The harmonic content shows the effect of the soft‐starter in exciting high‐frequency components of the line current. Harmonics investigations show that the high frequencies – even or odd multiples – of the fundamental line frequency are all excited by the soft‐starter approach. Some of these frequencies may harm the life cycle of the air‐conditioner.

Research limitations/implications

The real data harmonic analysis shows that the adopted approach excites the entire frequency spectrum of the signal. A better monitoring of the harmonics is required. A closed loop adaptive soft‐starting control may perform much better than a time‐based soft‐starting strategy.

Originality/value

The paper assesses the power quality related to time‐based soft‐starting strategy of a residential air‐conditioning system to reduce the inrush current and the dip in voltage, both with a serious effect on energy savings, especially when the AC load is around 65 per cent of the total power demand load.
A DTC strategy dedicated to three‐switch three‐phase inverter‐fed induction motor drives
Authors: Ben Rhouma Asma , Masmoudi Ahmed
Published: September 2008

Purpose

The purpose of this paper is to describe the implementation of a direct torque control strategy dedicated to three‐switch three‐phase delta‐shaped inverter (TSTPI) fed induction motor drives as well as the comparison of its performance with those yielded by six‐switch three‐phase inverter (SSTPI) fed induction motor drives under the Takahashi DTC strategy.

Design/methodology/approach

Referring to the asymmetrical stator voltage vectors and in order to reach high dynamic with low ripple of the electromagnetic torque response, the design of the vector selection table should include virtual voltage vectors by the subdivision of each sector into two equal sub‐sectors.

Findings

It has been shown that the implementation of the proposed DTC strategy in TSTPI‐fed induction motor drives leads to higher transient behaviour and better steady‐state features than those exhibited by the Takahashi DTC strategy implemented in SSTPI‐fed induction motor drives.

Research limitations/implications

The research should be extended to a comparison of the obtained simulation results with experimental measurements.

Practical implications

A 50 per cent reduction of cost and compactness associated with a 50 per cent increase of reliability makes the TSTPI an interesting candidate, especially in large‐scale production applications such as the automotive industry.

Originality/value

The paper proposes an approach to improve the cost‐effectiveness, the compactness and the reliability of TSTPI‐fed induction motor drives, which represents a crucial benefit in electric and hybrid propulsion systems.
Modelling and control of cascaded multilevel converters for dynamic compensation
Authors: Jaafar Imen , Ben Ammar Faouzi , Elleuch Mohammed
Published: September 2008

Purpose

This paper aims to integrate cascaded multilevel converters in the static compensator (STATCOM) systems in order to assure dynamic compensation of the reactive power absorbed by fixed speed wind turbines.

Design/methodology/approach

The cascaded multilevel converter topology is incorporated as a variable source of reactive power required by the wind farm. The evaluation of reference reactive currents is assured by the technique of instantaneous power theory. Thus, the STATCOM, with its appropriate control strategy, continuously compensates the reactive currents.

Findings

A developed non‐linear state representation makes possible the analysis of static and dynamic behaviour of the proposed system. The STATCOM‐based cascaded multilevel converter is able to provide continuous compensation and proves highly dynamic under steady state and transient operating conditions.

Practical implications

The paper formulates a mathematical model which includes all parameters describing the system composed by a medium voltage network, a wind farm and a STATCOM‐based cascaded multilevel converter. The study may help to develop new control methods of such power systems containing non‐linearities and an extended number of parameters.

Originality/value

Since there are few studies on comprehensive and complete models of power systems, the paper contributes to make both a study and a simulation based on a developed non‐linear state model which perfectly describes the state and transient behaviour of the proposed system.
Theory of the adjustable speed generation systems
Authors: Koczara Wlodzimierz , Chlodnicki Zdzislaw , Ernest Emil , Krasnodebski Artur , Seliga Robert , Brown Neil L. , Kaminski Bartlomiej , Al‐Tayie Jawad
Published: September 2008

Purpose

The purpose of this paper is to provide a new theory of adjustable speed decoupled generation which has the potential to challenge existing coupled generation based on a classical synchronous generator operating with fixed speed.

Design/methodology/approach

The paper's approach is a theoretical consideration of the drawbacks of conventional fixed speed generation based on a synchronous generator and proposal of problem solutions by the introduction of a decoupled generation system with additional degree of freedom. Computer calculations are used as design and for preliminary verification. Tests in a real laboratory system equipped with modern components such as electrical machines and power electronic converters proved the theory.

Findings

Decoupled generation is realized in a very original way using new blocks, integration method and control. The developed system has been awarded more than six world patents. The system has additional degrees of freedom in speed and grid connection operation.

Originality/value

The research team has concentrated its research over many years and developed a generation system which has been awarded a great number of patents. A special axial flux, light and simple permanent magnet generator was developed and integrated to the prime mover. A three‐phase AC/AC power electronic converter and a DSP controller are integrated to a very small size and low weight. The invented topology provides a very reliable operation, high‐quality AC voltage in fully three‐phase non‐symmetrical load. There were also presentations on world conferences (EPE, PESC, EPE‐PEMC).
An efficient approach to detect and classify power quality disturbances
Authors: Radil Tomáš , Janeiro Fernando M. , Ramos Pedro M. , Cruz Serra A.
Published: September 2008

Purpose

The purpose of this paper is to develop a new method for detection and classification of power quality disturbances such as transients, waveform distortions, sags, swells and interruptions.

Design/methodology/approach

For the purposes of the proposed method, the power quality disturbances are divided into two groups. Different algorithms are applied to detect and classify the disturbances from each of the two groups. For the processing of transients and waveform distortions, digital high‐pass filter and the mathematical morphology closing are used. Calculation of the RMS value is used for detection of sags, swells and interruptions.

Findings

The proposed method was implemented in a PC‐based measuring setup. The measuring setup was used in a seven‐months‐long monitoring of a single‐phase power system. In the course of the monitoring, the proposed method was verified on over 19,000 transients, 3,500 waveform distortions, 77 sags and 18 interruptions.

Research limitations/implications

The classification stage of the proposed method does not differentiate between individual types of waveform distortions (harmonics, interharmonics, noise…).

Practical implications

The described approach is simpler and more reliable than, for example, methods based solely on wavelet transform. The proposed method is suitable for real‐time monitoring of power systems.

Originality/value

The paper describes a new and efficient way of detection and classification of disturbances (especially of transients and waveform distortions). It shows that mathematical morphology operations, which are normally used in image processing, represent a useful tool also in the field of power quality measurements.
New reactive power sources dispatch applied to the IEEE 57 nodes
Authors: Belazzoug Messaoud , Boudour Mohamed , Hellal Abdelhafid
Published: September 2008

Purpose

The purpose of this paper is to deal with a new dispatching and optimization of reactive power sources in power systems.

Design/methodology/approach

The methodology is first based on an optimal movement of existing reactive sources as a first phase, then an optimal investment in a second phase and finally a combination of the two previous phases as the third one. The methodology showed also the advantage of a two‐levels procedure, considering an initial minimal compensation before minimizing the active losses. The solution of the global non‐linear problem is performed using the projected and augmented Lagrange method associated with the reduced gradient and the DFP methods.

Findings

In waiting for new investment programs which are planned for limited periods, the study presents an alternative of optimizing the reactive power compensation by a movement of the power sources or some of them, satisfying all system constraints and minimizing also the active power losses.

Originality/value

The planners and operators are able to decide what cases are to be considered for reactive power dispatch; the proposed program gives a proposal solution to almost all changes that can occur to the power system (incident, contingency, load variation, development).
Familiarity, expertise and involvement: key consumer segmentation factors
Authors: Taylor‐West Paul , Fulford Heather , Reed Gary , Story Vicky , Saker Jim
Published: September 2008

Purpose

It is generally accepted that the launch of a new product is critical to its success. Key to this is that manufacturers understand the market segment which is targeted for the launch. However, recent research and criticism suggest that modern segmentation strategies, aligning products with lifecycle typologies do not work. It is no longer possible to align consumers and products into neat and stable lifecycle segments. It is suggested that more importance should be attached to products having a familiarity fit with consumers – what they know and expect from a particular product. These views are moderated by a consumer's enthusiasm or involvement with the product as well as their level of expertise in understanding complex products. This paper aims to look at these issues.

Design/methodology/approach

This research looks at consumer perceptions to the changes to two automotive models launched by one of the major manufacturers at the Frankfurt Motor Show, Germany, held in September 2005, to discover which changes had the most appeal and to identify correlations with consumer lifecycles.

Findings

Results revealed that consumer lifecycles had no correlation with any of the data, whereas familiarity, expertise and product involvement will provide manufacturers with more accurate segmentation tools in the launch and marketing of new automotive products.

Practical implications

These findings suggest that a customer's expertise, product involvement and familiarity with the product are likely to provide more appropriate market segmentation tools.

Originality/value

This paper reveals useful information on consumer lifestyles and market segmentation tools.
Are pub discount cards loyalty cards?
Authors: Hobbs Rachel , Rowley Jennifer
Published: September 2008

Purpose

This research aims to explore the extent to which pub or bar discount cards that are distributed to students function as loyalty cards, or make a contribution to relationship building. The research also aims to make a contribution to the role of “instant discount” loyalty cards.

Design/methodology/approach

Data were collected on the design of the discount card schemes, their advantages and disadvantages from the customer and management perspective, the business motivations for introducing the scheme, the student motivations in purchasing the cards, and the impact of membership on profitability, popularity of venues, and repeat visits. Three main methods of data collection were used: questionnaires to collect a profile of customers' views; a focus group to gain a more in‐depth understanding of customer attitudes and behaviour; and, interviews with pub managers to understand the operation of the scheme and their perceptions of the impact of the scheme.

Findings

Pub discount cards do not generate either behavioural or attitudinal loyalty directly, but indirectly through the issue of a discount card, whose associated discounts cause a “flocking” behaviour through which the atmosphere in the pub is enhanced and its popularity and patronage are increased. The relationship between the customer and the pub is then mediated by customer‐to‐customer interactions and, thereby, in turn the discount cards “add value” for both customers and businesses.

Originality/value

This research makes a contribution to the use of discount/club cards in the hospitality sector, outside of the major schemes such as airline and hotel reward schemes. In addition, research into the use of these schemes provides a unique opportunity to understand the way in which the student demographic adopts and uses loyalty and discount cards.
The largest segments that should not be served: higher education marketing serving the growing slacker segment
Authors: Rotfeld Herbert Jack
Published: September 2008

Purpose

The purpose of this paper is to recognize how common practices of selling textbooks to university educators provide the tools for the faculty to minimize their teaching efforts. When coupled with higher education practices that see students as customers, such as university administrators' day‐to‐day goals driven by concerns of complaint avoidance, students “voting with their feet” for popular courses or the evaluation of teaching by use of students' evaluations of faculty, actual education gets minimized.

Design/method/approach

The paper describes common supplemental teaching aids provided to adopters of textbooks, but noting that the extensive use of these tools results in decreasing outcomes of student learning. The textbook publishers are using good marketing practices in that these textbook supplements target faculty who teach large numbers of students every year. In turn, the faculty who rely on these aids can become very popular with students. However, marketing to these segments of faculty and (indirectly) to these students might actually encourage the growth of these segments to the detriment of the smaller numbers of students who actually want an education and faculty would be willing to do the work to provide it.

Findings

The paper finds that, while popular attention such as the US “No Child Left Behind” legislation has been toward the primary education levels to ensure students are actually learning to read and write and while high schools increasingly use high stakes testing before students are allowed to graduate, the marketing practices of higher education could be serving the decline of thinking among college graduates. Textbooks target sales to faculty who want quantities of teaching aids to simplify the work, and schools can make classes more popular by asking students to do less thinking.

Originality/value

The paper provides a critical statement of common higher education practices that are not widely known or whose dangers are ignored.