bluuebunny/crossref_metadata_2025_split huggingface dataset:
Large‐signal device simulation in time‐ and frequency‐domain: a comparison
Authors: Bertazzi Francesco , Bonani Fabrizio , Donati Guerrieri Simona , Ghione Giovanni 
Published: November 2008

PurposeThe aim of this paper is to compare the most common time‐ and frequency‐domain numerical techniques for the determination of the steady‐state solution in the physics‐based simulation of a semiconductor device driven by a time‐periodic generator.Design/methodology/approachThe shooting and harmonic balance (HB) techniques are applied to the solution of the discretized drift‐diffusion device model coupled to the external circuit embedding the semiconductor device, thus providing a fully nonlinear mixed mode simulation.FindingsThe comparison highlights the strong and weak points of the two approaches, basically showing that the time‐domain solution is more robust with respect to the initial condition, while the HB solution provides a more rapid convergence once the initial datum is close enough to the solution itself.Originality/valueThe contribution compares two numerical techniques for the determination of the steady‐state solution of nonlinear dynamical systems, popular in the area of RF circuit analysis but rarely applied to device simulation. In particular, this is the first application of the shooting method to forced devices.
Symmetrical and Clarke‐Park transformations for four‐phase systems
Authors: Della Torre Francesco , Leva Sonia , Paolo Morando Adriano 
Published: November 2008

PurposeTo provide a unified analytical tool for the theoretical and practical analysis of four‐phase systems under sinusoidal condition but also under dynamic condition and to understand the contribution of each sequence components on the energy and air gap field points of view.Design/methodology/approachStarting from the general procedures of analysis for then‐phase symmetric systems, the analysis of four‐phase system is first developed in the phasorial domain, then, with reference to the asymmetrical sinusoidal conditions in terms of symmetric components. As a complement to what is already present in the literature, finally a formalization of the four‐phase systems in an instantaneous form based on the Lyon and Clarke‐Park vectors is proposed. Furthermore, a particular emphasis will be given to the physical meaning of the involved quantities, to their link with the three‐phase quantities and to the instantaneous energetic interpretation.FindingsFour phase system presents the existence of the pseudozero‐sequence component which is an additional descriptive variable of the four‐phase configuration, absent in the three‐phase system. Pseudozero‐sequence component results completely independent on the need for a neutral wire. Knowledge of the Park vector is as much as necessary to generate the field in the air gap.Practical implicationsThe four‐phase systems methodological analysis presented in this paper is very helpful for the formalization of the theoretical and applicative methodologies necessary for the development of four‐phase systems in a systematic and unified way.Originality/valueThe four‐phase systems analysis is presented in this paper both for the sinusoidal and the variable conditions. Furthermore, the role of the pseudozero‐sequence component, not present in three‐phase case, and its implications in circuital terms have been investigated with attention. Finally, the energetic side and the definition of the correspondent instantaneous and average powers have been investigated as well.
Adaptive neural network based controller for direct torque control of PMSM with minimum torque ripples and EMI noise reduction
Authors: Gulez Kayhan 
Published: November 2008

PurposeThe paper aims to provide an adaptive neural network controller for permanent magnet synchronous motor (PMSM) under direct torque control (DTC) algorithm to minimize the torque ripple and EMI noise.Design/methodology/approachThe design methodology is based on vector control used for electrical machines. MATLAB simulations supported with experimental study under C++ are used.FindingsThe simulated and experimental results show that considerable torque ripple as well as current ripple and EMI noise reduction can be achieved by utilizing adaptive neural switching algorithm to fire the inverter supplying the PMSM.Research limitations/implicationsThis research is limited to PMSM, however the research can be extended to include other AC motors as well. In addition, the following points can be studied: the effects of harmonics in control signals on the torque ripple can be analyzed; the actual mathematical relation between the torque and flux ripple can be studied to set the flux and torque bands width in reasonable value; different neural network algorithms can be applied to the system to solve the similar problems.Practical implicationsBased on existing DTC control system, it is only required to change the software switching algorithm, to provide smooth torque, given that the switching frequency of the inverter module is more than or equal to 15 MHz and the system is supplied with timers. In addition a relatively higher DC voltage may be required to achieve higher speed compared with the traditional DTC.Originality/valueIn this paper, the stator flux position, and errors due to deviations from reference values of the torque and stator flux are used to select two active vectors while at the same time the absolute value of the torque error and the stator flux position are used neural network structure to adapt the switching of the inverter in order to control the applied average voltage level in such a way as to minimize the torque ripple, so instead of fixed time table structure, a neural network controller is used to calculate the switching time for the selected vectors and no PI controller is used as the case in the traditional space vector modulation. This work is directed to motor drive system designers who seek highly smooth torque performance with EMI noise reduction.
Novel Padé‐based algorithms for numerical integration of ODEs
Authors: Condon Marissa , Dautbegovic Emira , Xu Tao 
Published: November 2008

PurposeThe paper aims to propose several new approaches for the discrete‐time integration of stiff non‐linear differential equations.Design/methodology/approachThe proposed approaches build on a method developed by the authors involving Padé approximates about each function sample. Both single‐ and multi‐step methods are suggested. The use of Richardson extrapolation is recommended for increasing efficiency.FindingsThe efficacy of the methods is shown using two examples and results are compared to a standard integration technique.Originality/valueThe paper shows that the methods are suitable for application in any field of science requiring efficient and accurate numerical solution of stiff differential equations.
Locally coupled magneto‐mechanical model of electrical steel
Authors: Belahcen A. , Arkkio A. 
Published: November 2008

PurposeThe purpose of this paper is to find out how to model the effect of mechanical stresses on the magnetic properties of electrical steel used in electromagnetic devices and especially in electrical machines. Further, the effect of these stresses on the operation of the machines should be studied.Design/methodology/approachThe constitutive equation of the electrical steel is usually modeled as a non linear relation between the magnetic flux density and the magnetic field strength. In this research, this constitutive equation is developed to account for the mechanical stresses through a parametric relationship, the parameters of which are estimated from measurements. Further, the constitutive equation is used in a magnetomechanically coupled numerical simulation of an induction machine.FindingsThe mechanical stresses degrade the properties of the electrical steel and increase the magnetization current in electrical machines. This leads to a decrease in the efficiency of these machines.Research limitations/implicationsThe effect of mechanical stresses is studied from the point of view of magnetization properties. This work does not model the effect of stresses on the specific losses of the material. Such a research is still going on.Originality/valueThe effect of mechanical stress on the magnetic properties of the materials used in electrical machines is modeled in an easy and original way, which allow for its application in numerical simulation and analysis of these machines.
Determining the range of real eigenvalues for the interval generalized eigenvalue problem
Authors: Kolev L. 
Published: November 2008

PurposeTo suggest a polynomial complexity method for determining the range of real eigenvalues in the case of the generalized eigenvalue problem when the elements of the matrices involved are independent intervals.Design/methodology/approachThe basic approach is to make use of approximate interval solutions as regards the right and left eigenvectors of the eigenproblem considered, the so‐called outer solutions, in order to determine the range.FindingsFirst, a new method for computing the outer solutions has been suggested. The main result of the paper, however, is the development of a simple method for determining the range of the real eigenvalues. Unlike the known general‐purpose methods that have exponential complexity, the present range determination method is much simpler as its complexity is only polynomial.Research limitations/implicationsThe method is applicable if certain sufficient conditions reported in the paper are satisfied (an incomplete quadratic system is to have a positive solution and the signs of the outer solutions should satisfy a complete or partial invariance).Practical implicationsThe method guarantees reliable numerical results when the original eigenproblems contain interval uncertainties as is, strictly speaking, most often the case in practice.Originality/valueTo the best of the author's knowledge, the present paper suggests, for the first time, a simple method of polynomial complexity for solving the problem considered which is inherently a NP‐hard problem (of exponential complexity).
Jumping in at the deep end: young professionals and peer‐reviewed journals
Authors: Greifeneder Elke 
Published: November 2008

PurposeThe purpose of this paper is to discuss research articles from authors who have just left school.Design/methodology/approachThis is an opinion piece.FindingsBad research should not be accepted just to help young professionals get published, but the best can be offered opportunities like this special issue with explicit invitations to publish their research via a peer‐review process.Originality/valueThis paper identifies the potential of young professionals and peer‐reviewed journals.
Talking, looking, flying, searching: information seeking behaviour in Second Life
Authors: Ostrander Margaret 
Published: November 2008

PurposeThis research seeks to answer, “How do everyday Second Life users go about finding needed information?” as the primary research question.Design/methodology/approachA virtual ethnographic approach couched in grounded theory was utilized to conduct semi‐structured interviews with everyday users of Second Life, accompanied by participant observation.FindingsInformation seeking behaviors within the virtual world of Second Life were found to be rich, complex interaction with multiple facets. Five themes emerged to illuminate how users seek information.Research limitations/implicationsThis research took place over a six‐week period, although most enthographies last at least one year. Conclusions were drawn solely from interviews because participant observation did not penetrate a given community with enough depth to adequately address the research question.Practical implicationsVirtual worlds offer the promise of becoming an integrated part of the information seeking landscape for an increasing number of users. Understanding the factors influencing information seeking behavior that are outlined in this article will equip librarians and information professionals to best utilize virtual worlds and continue to create innovative, user‐focused services there.Originality/valueThis article extends current scholarship by offering a practical, five‐factor approach to understand how people seek information in virtual worlds. The literature is robust in description about library services and the nature of information in virtual worlds. Yet, investigation into information seeking behavior in this environment is in its nascent stages.
Facebook as a social search engine and the implications for libraries in the twenty‐first century
Authors: Scale Mark‐Shane 
Published: November 2008

PurposeThe primary objectives of this research paper are to explore the concept of social search, evaluate the performance of Facebook as a social search engine, and to understand the relationship between social networking sites (SNS) and social search. The author's intention is to examine the possibility that Facebook presents as the future of on‐line search and the implications for libraries.Design/methodology/approachThis study reviews the literature on SNSs, Facebook studies, and the concept of social search. It then explores Facebook as a social search engine through participant observation, personal experience and experiment. The experiment is based on two identified search queries. Both queries are performed, wherein the results retrieved are displayed using tables and evaluated.FindingsFacebook as a people search engine, yields irrelevant results in response to search queries for unknown persons or groups. Facebook may also fail to provide timely and relevant results when attempting to get information from persons with whom the user has a weak relationship. Findings also indicate the limitations of users functioning as quasi‐librarians as it relates to the quality of information retrieval.Practical implicationsThe findings are relevant for library and information science academics and professional practitioners.Originality/valueThe author provides an approach for evaluating the quality of information retrieval in social search using the traditional information retrieval evaluation methods of library and information scientists. He also revisits old arguments on the importance of the profession to web information in light of new trends and data.
Collaboration as a wave of future: exploring experiences from Croatian archives
Authors: Faletar Tanackoviæ Sanjica , Badurina Boris 
Published: November 2008

PurposeThe purpose of this paper is to report on research that examined the relationship between, and collaboration of, Croatian archives, libraries and museums.Design/methodology/approachOnline survey and unstructured interviews with archivists from across Croatia were used to investigate collaborative activities in Croatian archives.FindingsArchivists see libraries and museums as their natural partners and believe that collaboration facilitates their mission and leads to better service to patrons. However, they all believe that there is room for more intensive inter‐institutional partnerships. Apart from numerous benefits, they also indicated a number of challenges they face in collaborative activities.Research limitations/implicationsA larger sample for qualitative methodology would greatly serve to clarify and expand upon the findings.Practical implicationsThe results of this survey are useful to cultural heritage professionals in planning and organisation of collaborative projects. Also, government and authorised institutions can learn about what kind of support archives would need to embark on a more intensive collaboration.Originality/valueTo the author's knowledge, this is the first work that looks in detail into collaborative activities of archives. As far as the authors are aware, similar investigations have been carried out regarding library and museum collaboration only.
Reappraising archival practice in light of the new social history
Authors: Van Wingen Melinda , Bass Abigail 
Published: November 2008

PurposeThis paper aims to explore the relationship between historiography and archival practices. It takes the new social history approach to history as a case study for examining how historians' changing theories and methods may affect solicitation, acquisition, appraisal, arrangement, description, reference, outreach, and other aspects of archival administration.Design/methodology/approachThe paper presents a review of the archival and historical literature since the late 1970s.FindingsThe paper finds that many aspects of archival administration have been and continue to be affected by the new social history trend in historical scholarship. The paper suggests that archivists and archival educators be trained in historiography as a way to understand historians' craft and develop strong documentation strategies to anticipate future archival needs.Research limitations/implicationsBecause the paper is primarily a literature review, it does not test real‐life examples or case studies that would be useful in understanding the relationship between historians and archivists.Practical implicationsThe paper includes implications for the development of archival administration and education strategies.Originality/valueThe paper draws from a range of literature to consider the impact of scholarly practices on professional archival work.
Exploring access in the developing world: people, libraries and information technology in Morocco
Authors: Lea Moulaison Heather 
Published: November 2008

PurposeThis paper aims to explore the information technology environment in a developing country, Morocco, through a discussion of the people, their information environment, and libraries. Concepts of modern library and information studies (LIS) education and the new role of the library professional in this context are also to be explored.Design/methodology/approachLargely based on a review of literature on the people, their information environment, and technology in Morocco, this paper incorporates both synthesis and discussion from an LIS point‐of‐view.FindingsBasic elements of the culture make library work difficult in Morocco. In reflecting on other cultures and participating in the international LIS dialogue, librarians can develop new perspectives on difficulties they experience at their home institutions while contributing to solutions of problems abroad.Practical implicationsBy supporting library work in developing countries, western librarians can have a positive impact on users both at home and abroad.Originality/valueThird world librarianship is not a phenomenon happening “over there” in a vacuum – real librarians trained in library and information science in countries like Morocco are helping users to access information. Their work contributes to the international conversation taking place in LIS, a discussion that is ultimately of benefit to all involved.
Digital rights description as part of digital rights management: a challenge for libraries
Authors: Böhner Dörte 
Published: November 2008

PurposeThe purpose of this paper is to answer the question of whether digital rights management (DRM) can be useful to libraries.Design/methodology/approachThe paper provides a legal and technical description of DRM and its current and future opportunities.FindingsThe paper finds that digital rights management has possibilities that can be useful for libraries. But it is important that librarians become more active in the standardization and development of new ideas. Some examples are given.Originality/valueThe paper offers a realistic approach to DRM for libraries.
Recruiting for diversity: strategies for twenty‐first century research librarianship
Authors: Dewey Barbara , Keally Jillian 
Published: November 2008

PurposeThe paper aims to focus on organizational and institutional strategies, including a case study from the University of Tennessee, concerned with recruiting librarians from diverse backgrounds.Design/methodology/approachPrograms from the Association for Research Libraries, the American Library Association, OCLC, and IFLA for recruiting librarians from diverse backgrounds are reviewed. An in‐depth case study of the University of Tennessee Diversity Libraries Residency Program is included to provide a detailed example of a successful program and its contributions locally and to the research library field.FindingsThe paper provides strategies and a catalyst for other organizations and institutions to develop robust recruitment programs for a diverse workforce in academic libraries.Originality/valueThis paper lays out strategies for robust diversity recruiting activities at the organizational and institutional level using the University of Tennessee's experiences as a basis for discussion.
A survey of the application of Web 2.0 in Australasian university libraries
Authors: Cuong Linh Nguyen 
Published: November 2008

PurposeThis paper aims to provide an overall picture of the application of Web 2.0 technologies in Australasian university libraries. The focus of the research was what types of Web 2.0 technologies were applied in such libraries as well as their purposes and features.Design/methodology/approachContent analysis was used in terms of quantitative approach. A checklist as the main research instrument was developed based on other checklists and questionnaires, and synthesized ideas from literature. Data were collected by accessing all Australasian university library web sites within two weeks. Then, Microsoft Excel was utilized as a main tool to synthesize and analyze data, and present results.FindingsAt least two‐thirds of Australasian university libraries deployed one or more Web 2.0 technologies. Only four Web 2.0 technologies were used for specific purposes and with some basic features. The general Web 2.0 application indexes were still low as the mean application index was 12 points and the highest index was 37 points (out of 100).Research limitations/implicationsA combination of content analysis with survey and/or interview may enable future researchers to analyze other aspects (e.g. the application of internal wikis or the use of instant messaging for reference services) of Web 2.0 that a single method of content analysis could not gain.Originality/valueThis unique study explores the application of Web 2.0 in a wide scope including any Australasian university libraries that deployed any types of Web 2.0 technologies. This study is useful for Australasian university libraries in evaluating/deploying Web 2.0. Library managers, librarians and other university libraries may also find this helpful once they want to implement such technologies in their libraries.