bluuebunny/crossref_metadata_2025_split huggingface dataset:
The non‐monotonic effect of real wages on labour productivity
Authors: Foon Tang Chor 
Published: May 2012

PurposeThe aim of this study is to empirically investigate the effect of real wages on labour productivity in Malaysia's manufacturing sector using annual data from 1980 to 2009.Design/methodology/approachThis study uses the Johansen cointegration test to examine the presence of long‐run equilibrium relationship between labour productivity and real wages in Malaysia. In addition, the Granger causality test within the vector error‐correction model (VECM) is used to ascertain the direction of causality between the variables of interest.FindingsThe Johansen test suggests that real wages and labour productivity are cointegrated. Moreover, labour productivity and real wages have a quadratic relationship (i.e. inverted U‐shaped curve) instead of linear relationship. Hence, the effect of real wages on labour productivity is non‐monotonic. Furthermore, the Granger causality test indicates that real wages and labour productivity are bilateral causality in nature.Research limitations/implicationsThis study is limited to the labour productivity in the manufacturing sector only.Originality/valueThis study demonstrates that the effect of real wages on labour productivity is non‐monotonic; hence increase in real wages alone does not always enhance labour productivity. Thus, other incentives should be offered to stimulate long‐term labour productivity growth in Malaysia.
Optimal shape design with field subdomains modeled by Thévenin equivalent conditions
Authors: Di Barba Paolo , Savini Antonio 
Published: May 2012

PurposeThe purpose of this paper is to propose a method, reducing the order of the analysis problem, to help the solution of optimal shape design problems in electricity and magnetism.Design/methodology/approachThe proposed method, the background of which relies on the generalized Thévenin theorem, exploits a principle of field diakoptics.FindingsAfter assessing the proposed method on a benchmark of inverse magnetostatics, the shape optimisation of the stress‐control ring in a power transformer is considered as the case study.Originality/valueThe proposed method makes it possible to reduce the cost of an optimisation procedure, when the direct problem is solved by means of finite‐element analysis.
Magnetic field mitigation by means of passive loop: technical optimization
Authors: Canova Aldo , Fabio Freschi , Giaccone Luca , Guerrisi Alessandra , Repetto Maurizio 
Published: May 2012

PurposeThe purpose of this paper is to present an approach to design passive loop systems in order to reach good performances.Design/methodology/approachThe optimization has been performed by means of the MATLAB optimization toolbox “Gatool” which solves the optimization problems with a genetic algorithm.FindingsSeveral configurations have been analyzed by varying the number of loops from 2 to 15, whose geometry has been chosen by the genetic algorithm. Considering a five loops configuration, along the reference path it is possible to obtain a shielding factor almost constant and equal to 3.5.Originality/valueThe optimized configurations have been compared with a practical employed layout composed of 17 closed loops placed above and around the junction zone. The shielding factors obtained by the six loops configuration are comparable with the ones of the practical layout.
Space mapping methodology for defect recognition in eddy current testing – type NDT
Authors: Putek Piotr , Crevecoeur Guillaume , Slodička Marian , van Keer Roger , Van de Wiele Ben , Dupré Luc 
Published: May 2012

PurposeThe purpose of this paper is to solve an inverse problem of structure recognition arising in eddy current testing (ECT) – type NDT. For this purpose, the space mapping (SM) technique with an extraction based on the Gauss‐Newton algorithm with Tikhonov regularization is applied.Design/methodology/approachThe aim is to have a computationally fast recognition procedure of defects since the monitoring results in a large amount of data points that need to be analyzed by 3D eddy current model. According to the SM optimization, the finite element method (FEM) is used as a fine model, while the model based on an integral method such as the volume integral method (VIM) serves as a coarse model. This approach, being an example of a two‐level optimization method, allows shifting the optimization load from a time consuming and accurate model to the less precise but faster coarse surrogate.FindingsThe application of this method enables shortening of the evaluation time that is required to provide the proper parameter estimation of surface defects.Research limitations/implicationsIn this work only the specific kinds of surface defects were considered. Therefore, the reconstruction of arbitrary shapes of defects when using real measurement data from ECT system can be treated in further research.Originality/valueThe paper investigated the eddy current inverse problem. According to aggressive space mapping method, a suitable coarse model is needed. In this case, for the purpose of 3D defect reconstruction, the reduced VIM approach was applied. From a practical view point, the authors demonstrated that the two‐level inversion procedures allow saving of up to 50 percent CPU time in comparison with the optimization by means of regularized Gauss‐Newton algorithm in the same FE model.
Problem formulation and analysis for optimal energy management in multisources systems: W effect
Authors: Warkozek Ghaith , Ploix Stéphane , Wurtz Frédéric , Jacomino Mireille , Delinchant Benoit 
Published: May 2012

PurposeThe purpose of this paper is to introduce a problematic phenomenon that can occur when managing multi electrical sources systems by optimization.Design/methodology/approachThe energy management problem is formulated as a linear optimisation problem. Two approaches are developed and applied to detect the possible existence of equivalents solutions. The first is based on Dulmage‐Mendelsohn (DM) decomposition. With this method the structure of the optimisation problem is analysed. The second approach is a numeric approach; the detection of equivalents solutions is made by the formulation of new optimisation problem and the objective function of this problem is to maximise the distance between two equivalents solutions.FindingsThe numeric approach is more efficient than the structural approach. In some cases, applying DM decomposition may not be sufficient to detect the risk of W effect. This is because DM decomposition does not take the value of variable's coefficient into consideration, which is important to determine the degrees of freedom in the set of variables.Originality/valueMulti sources systems are widely used, especially in buildings where renewable energies have good potential application. The linear formulation of the management problem may induce an existence of equivalent command strategies. The detection approach presented in this paper shows that some solutions are better than others from an applicabability point of view. They will not exhaust rapidly the storage system. This approach can be implemented in virtual sources plant to avoid solutions with this so‐called W effect.
Clustering analysis of railway driving missions with niching
Authors: Jaafar Amine , Sareni Bruno , Roboam Xavier 
Published: May 2012

PurposeA wide number of applications requires classifying or grouping data into a set of categories or clusters. The most popular clustering techniques to achieve this objective are K‐means clustering and hierarchical clustering. However, both of these methods necessitate the a priori setting of the cluster number. The purpose of this paper is to present a clustering method based on the use of a niching genetic algorithm to overcome this problem.Design/methodology/approachThe proposed approach aims at finding the best compromise between the inter‐cluster distance maximization and the intra‐cluster distance minimization through the silhouette index optimization. It is capable of investigating in parallel multiple cluster configurations without requiring any assumption about the cluster number.FindingsThe effectiveness of the proposed approach is demonstrated on 2D benchmarks with non‐overlapping and overlapping clusters.Originality/valueThe proposed approach is also applied to the clustering analysis of railway driving profiles in the context of hybrid supply design. Such a method can help designers to identify different system configurations in compliance with the corresponding clusters: it may guide suppliers towards “market segmentation”, not only fulfilling economic constraints but also technical design objectives.
Inverse source problem for thermal fields
Authors: Marinova Iliana , Mateev Valentin 
Published: May 2012

PurposeThe purpose of this paper is to develop an inverse approach for 3D thermal sources determination.Design/methodology/approachThe developed approach is based on the Green's function for Poison's equation. Forward and inverse couple electromagnetic‐thermal field problems are formulated. Finite elements models are built and applied. Thermal field data are acquired by thermo vision camera. The thermal field sources are determined inside of the investigated inaccessible volume object using modeled and measured data with the developed approach.FindingsThe presented method and implemented examples demonstrate the possibilities of the developed approach for inverse source problem solution and determination of thermal field distributions of electrical devices.Originality/valueThe proposed inverse method uses the Green's function for Poison's equation for solution of thermal field problem taking into account the couple electromagnetic‐thermal problems. Proposed inverse method is very fast, accurate and can be used in many practical activities for electrical current determination and visualization in inaccessible regions only by measured external thermal field. Thermal field data needed for the method are easily acquired by thermo vision camera.
Optimization of a permanent magnet needle actuator
Authors: Yatchev Ivan , Rudnicki Marek , Hinov Krastyo , Gueorgiev Vultchan 
Published: May 2012

PurposeThe purpose of this paper is to solve the optimization problem for a permanent magnet linear actuator with moving magnet for driving a needle in a knitting machine. The optimization is carried out with respect to the maximal average force along the stroke.Design/methodology/approachThe optimization factors are the dimensions of the permanent magnet and the pole length. For obtaining the objective function for each parameter combination, the static force‐stroke characteristic is computed. Three‐dimensional finite element analysis is employed for obtaining the electromagnetic force. The objective function is then approximated by secondary models on the basis of design of experiment. The optimization is carried out using sequential linear programming.FindingsOptimal solution to the problem has been obtained and the force‐stroke characteristic of the optimal actuator is given.Originality/valueThe proposed approach employs sequential linear programming with move limits using trust region concept, 3D finite element analysis, design of experiments and secondary models for optimization of a permanent magnet linear actuator for individual needle driving in a knitting machine.
Data errors influence on the robustness of problem solutions
Authors: Dimitrova Stancheva Rumena , Ilieva Iatcheva Ilona 
Published: May 2012

PurposeThe purpose of this paper is to evaluate the rate of discrepancy between the group of expected project results and the group of corresponding results realized preliminarily at the design stage.Design/methodology/approachThe authors formulate and solve the problem to determine the values of two assemblies of independent variables guaranteeing the project with the best (X→*) and as well this one with the worst (X→**) tolerance field of the expected Zx realization. The problem is formulated as an optimization one in nonlinear mathematical programming and it is solved by applying the flexible tolerance method.FindingsBy the use of basic relations in statistical science an expression of standard deviation σZx of Zx is found and proposed. The limits in which are expected to be change in the deviations between the main project results and the corresponding ones of the implemented design, mathematically defined previous to its realization.Research limitations/implicationsThe accent is put on the cases when the device characteristics are presented as polynomials, obtained on the bases of the design of experiments (DOE) and the response surface methodology. An arbitrary technical characteristic Zx=Z(x→) is presented.Practical implicationsA researcher could confine numerically the tolerance field between project results and expected realized ones in the whole investigated region.Originality/valueThe paper is characterized by an original approach and a new expression of standard deviation is proposed which will be of interest to designers.
TiO2‐SiO2 inorganic barrier composites: from synthesis to application
Authors: Siwińska‐Stefańska K. , Ciesielczyk F. , Kołodziejczak‐Radzimska A. , Paukszta D. , Sójka‐Ledakowicz J. , Jesionowski T. 
Published: May 2012

PurposeThe purpose of this paper is to report on a method of synthesis of TiO2‐SiO2 oxide composites characterised by spherically shaped particles with sizes in the micrometric ranges, which can be applied as a new generation of textile/TiO2‐SiO2 composites with barrier properties against UV radiation. Synthesis and characterisation of TiO2‐SiO2 oxide composites with a high degree of dispersion were performed, and their influence on the barrier properties of textile fabrics was investigated.Design/methodology/approachThe precipitation was performed with the use of solutions of titanium sulphate and sodium silicate as the precipitating agent, which are cheap alternatives to organic precursors of Ti and Si. The reaction was conducted in an emulsion system, where cyclohexane was used as the organic phase and non‐ionic surfactants NP3 and NP6 as emulsifiers were applied.FindingsThe direction of substrate supply, concentration of the reagents and their ratio and other conditions of precipitation process were found to significantly affect the physicochemical parameters of the pigments obtained. A possibility is provided of manufacturing a new generation of textile/TiO2‐SiO2 composites with barrier properties against UV radiation.Research limitations/implicationsTitanium sulphate, sodium silicate, cyclohexane as the organic phase, and non‐ionic surfactants NP3 and NP6 as emulsifiers, were used.Practical implicationsSynthesis of a new generation of textile/TiO2‐SiO2 composites with barrier properties against UV radiation has been performed. Textile fabrics modified with hybrid composites demonstrated high absorption of UV radiation over the full wavelength range.Originality/valueDetermination of optimum conditions of TiO2‐SiO2 oxide composites precipitation to obtain products with desired physicochemical, dispersive and structural properties. Development of nano‐structural textile composites with barrier properties, protecting against UV radiation.
Highly reflective titania nanoparticle‐based coating
Authors: Kumar Sanjeev , Verma Narendra K. , Singla Madan L. 
Published: May 2012

PurposeThe purpose of this paper is to investigate the reflective properties of titania (TiO2) nanoparticle‐based coating.Design/methodology/approachTiO2 nanoparticles, synthesised by sol‐gel method, were characterised by X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and ultraviolet‐visible absorption spectroscopy (UV‐vis). The coating material has been prepared by dispersing titania nanoparticles in an acrylic binder with different pigment to binder weight ratio. The reflectors were prepared by applying this coating material to different coating thicknesses to aluminium sheets.FindingsIn the study reported here, the coating material could produce reflectors with diffuse reflectance, ∼99 per cent, using coating material, having binder by weight ratio between 14 and 20 per cent, and thickness, 0.15 mm. On exposing the developed reflectors to different levels of illumination (upto 20,000 lux), they were still found to have diffuse reflectance of more than 96 per cent almost throughout the visible spectrum.Practical implicationsThe fabricated reflectors find applications in commercial optical products, such as: reflective panels, luminaries, etc.Originality/valueAs of today, the reflective coatings used are of conventional type, which employ bulk TiO2 particles. In this study, we are reporting TiO2 nanoparticle‐based highly reflective coating. This is an original work, and, to the best of our knowledge, no one has ever reported on “TiO2 nanoparticle‐based reflective coatings”.
Library Hi Tech and information science
Authors: Seadle Michael 
Published: May 2012

PurposeThis article aims to look at the relationship between Library Hi Tech and the academic field of information science.Design/methodology/approachThis is an opinion piece whose methodology is in part historical review, and in part observation of present and future trends.FindingsLibrary‐based information is no longer almost exclusively text. Research libraries in particular are increasingly responsible for numeric data sets in their repositories.Practical implicationsLibrarians need to think about information literacy not merely in terms of finding and evaluating traditional publisher data.Originality/valueThis paper reviews the relationship between Library Hi Tech and the academic field of information science, and observes present and future trends.
Keeping students engaged with web‐based polling in the library instruction session
Authors: Hoppenfeld Jared 
Published: May 2012

PurposeThis research was performed with the aim of determining the potential benefit(s) of including web‐based polling in the library instruction classroom.Design/methodology/approachOver the course of a year, web‐based polling was used in library instruction sessions and the survey results were recorded. Feedback forms were also used to gauge a sense of the students' experiences with this form of active learning.FindingsThis study found that web‐based polling in a library instruction classroom benefits both students and instructors. The students enjoy these sessions and are more attentive than in a typical lecture, which leads to better learning. Instructors are able to learn about the students' uses of technology, research methods, and more with the polling capability.Research limitations/implicationsThe research in this study was only done using the free version of Poll Everywhere in management classes. It would be interesting to see if the results would be the same in other business classes as well as non‐business classes. It could also be beneficial to test the functionality of paid accounts as well as seeing how other web sites compare.Practical implicationsThis article may assist those deciding between different audience response systems and provide tips to those wishing to implement web‐based polling, and more specifically Poll Everywhere, in their sessions.Originality/valueFew articles on audience response systems exist solely on web‐based polling and the benefits instructors can reap in addition to their students. This research will be of benefit to any librarian who teaches in the classroom, especially those in academic libraries.
Old wine in new wine skin: marketing library services through SMS‐based alert service
Authors: Paul Anbu K. John , Mavuso Makana R. 
Published: May 2012

PurposeShort Message Service (SMS) is an application which is widely used in mobile telephony. SMS messaging through mobile phones is very popular among young and old. This study aims to look at how SMS technology can be very effectively used in library and information services with a glimpse into a pilot project conducted by University of Swaziland and Emerald Group Publishing Limited and the subsequent need for creating a prototype for the SMS‐based library alert services and marketing of library services.Design/methodology/approachFollowing the pilot project conducted by the University of Swaziland and Emerald Group Publishing Limited for a period of two months (March‐April 2009), the findings and the methodology used for the project prompted further research. Data and experience gained during the pilot project is predominantly used in the paper.FindingsThis study finds that the library users can be successfully motivated and engaged to use the resources through SMS messaging and have the potential to market library services. It also finds out that there is a need to have a prototype for essential services for the benefit of the users as well as to market the library resources.Research limitations/implicationsThe pilot project was a short project with specific user base. This project was not tested on heterogeneous user base. The prototype model also works on certain assumptions and limitations. At the prototype level different files are suggested and they are handled separately because of which an open ended script method is suggested. Longer SMSs, which cannot be sent by the SMS server, need to be either split up into several messages or stored in the server as a webpage and sent as a hyperlink in SMSs.Practical implicationsTo implement the prototype, various steps highlighted in the paper are to be followed and since each action needs to be operated separately, it cannot be claimed as a single click SMS‐based alert service.Originality/valueThis study presents a method for implementing SMS‐based alert service in libraries. With the experience gained in a similar practical environment, an attempt has been made to create a prototype. This may serve as an important milestone in integrating such a service into the future integrated library services (ILS).
Understanding and exploiting idiosyncrasy in the use of ICT devices such as tablets
Authors: Fourie Ina 
Published: May 2012

PurposeWhen using information communication technology (ICT) devices it is easy to be trapped by purely the purpose of their design, how they are marketed, product reviews and noting, or even copying, the behaviour of the younger, Net Generation. The purpose of this column is to argue for encouraging all to contribute to deepening our understanding of fully exploiting technology. This includes encouraging people who may be less techno‐savvy but with a richer life‐world and life‐experience to share their use of devices such as tablets, and to allow all to benefit from the idiosyncrasy in use that should be aimed at a life‐fit with personality, learning style, preferences, etc., and widening information spaces and information horizons.Design/methodology/approachThe column is written against the background of research from information behaviour, and the learning sciences (especially andragogics).FindingsThere are many reasons to explore more than the obvious ways in which ICT devices such as tablets can be used, and for encouraging a spectrum of users to share the idiosyncrasies in their use thereof. Library and information (LIS) services should move from merely teaching people information literacy and ICT skills to creating grounds for sharing practices and experiences in using devices such as tablets. The focus should move to exploiting the benefit of exploring idiosyncrasies in ICT use and how to encourage people to reflect their life‐world and life‐experience in their use of ICT devices such as tablets to widen their (and our) information spaces and information horizons.Originality/valueAlthough much has been published on ICT in the library and information science literature and more recently in relation to the Net Generation, the author is not aware of publications exploiting idiosyncrasy and the value that can be added by considering the life‐world and life‐experience of people in their choices in using ICT devices such as tablets. This paper sets the background for further reflection.