bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel circuit model of a proton exchange membrane fuel cell
Authors: Guarnieri Massimo , Moro Federico 
Published: December 2010

PurposeThe purpose of this paper is to simulate passive proton exchange membrane fuel cells (PEMFCs) for portable electronic devices by means of a non‐linear lumped circuit based on electrical, mass transfer and electro‐kinetic equations.Design/methodology/approachElectrical, mass transfer and electro‐kinetic equations are combined in order to derive a non‐linear lumped circuit. The dynamic circuit model is tested in realistic operating conditions.FindingsAn original equivalent circuit model for simulating the transient behavior of passive PEMFCs is proposed. The PEMFC is represented as a non‐linear equivalent circuit with controlled lumped parameters depending on pressure, temperature, hydration, and system capacity.Research limitations/implicationsLumped parameters are synthesized assuming a one‐dimensional fuel cell model since layer thicknesses are much smaller than other dimensions. Heat generation and transfer are not modeled even though lumped parameters depend on temperature.Practical implicationsThe proposed circuit model can be implemented directly in circuit simulators for designing power management units needed to interface small‐passive PEMFCs and portable electronics such as PDAs, laptops, or mobile phones.Originality/valueThe fuel cell is represented as a non‐linear controlled generator whose parameters are derived directly from multiphysics equations rather than empirical relationships. The dynamic behaviour of PEMFCs can be simulated on completely different times scales, i.e. during transients or during the discharge phase.
Finite‐element analysis of a shielded pulsed‐current induction heater
Authors: Sabariego Ruth V. , Sergeant Peter , Gyselinck Johan , Dular Patrick , Dupré Luc , Geuzaine Christophe 
Published: December 2010

PurposeThe aim of this paper is the experimental validation of an original time‐domain thin‐shell formulation. The numerical results of a three‐dimensional thin‐shell model are compared with the measurements performed on a heating device at different working frequencies.Design/methodology/approachA time‐domain extension of the classical frequency‐domain thin‐shell approach is used for the finite‐element analysis of a shielded pulse‐current induction heater. The time‐domain interface conditions at the shell surface are expressed in terms of the average flux density vector in the shell, as well as in terms of a limited number of higher‐order components.FindingsA very good agreement between measurements and simulations is observed. A clear advantage of the proposed thin‐shell approach is that the mesh of the computation domain does not depend on the working frequency anymore. It provides a good compromise between computational cost and accuracy. Indeed, adding a sufficient number of induction components, a very high accuracy can be achieved.Originality/valueThe method is based on the coupling of a time‐domain 1D thin‐shell model with a magnetic vector potential formulation via the surface integral term. A limited number of additional unknowns for the magnetic flux density are incorporated on the shell boundary.
Virtual positioning and shaping of source fields for ECT of tubes
Authors: Ferraioli Fabrizio , Formisano Alessandro , Martone Raffaele , Iacotucci Francesco 
Published: December 2010

PurposeThe purpose of this paper is to present a new approach to drive the excitation field sources in the eddy current testing (ECT) of tubular conductive structures.Design/methodology/approachThe magnetic field used for ECT is generated by pairs of counter‐series connected coils, driven by AC currents. The phase and amplitude of the currents is electronically controlled in order to shape the primary field map, allowing circumferential sweeps until the presence of defects is detected, and then “focusing” the field on the defective section of the tube, increasing in this way the sensibility of the ECT probes in the targeted area, in order to determine with higher precision, the position, and the shape of the defect.FindingsIf suitably designed, the field measurement system allows to enable/disable a number of probes to enhance the resolution in the defect area while keeping low the number of required data channels.Research limitations/implicationsThe analyzed geometry is limited to circular‐shaped tubes, of infinite extent. Future work should be on the extension of the methodology to general shapes, and to finite length cylinders.Practical implicationsThe proposed method allows to enhance resolution in ECT of tubes at the end of production lines, guaranteeing a first, simple yet effective quality assessment of tubes in industrial environments.Originality/valueThe paper presents a new technique to test conductive tubes using fixed excitation system, but allowing to focus magnetic field in defective regions. The method could be helpful for industrial diagnostics.
Adaptation in coupled problems
Authors: Vokas Christos , Kasper Manfred 
Published: December 2010

PurposeThe purpose of this paper is to address the formulation, implementation, and adaptation of closely coupled multi‐physics problems withh‐ andp‐adaptive finite element methods. A general formulation is chosen allowing for coupled problems of various types. Adaptation algorithms forh‐ andp‐refinement are given.Design/methodology/approachA generic system of second‐order differential equations is used, where the field of each individual problem is represented as an entry in the list of field variables. Specific problems are implemented by mapping material coefficients to the coefficients of the generic form. An example with four natures is investigated with close coupling between electric, mechanical and thermal fields.h‐ andp‐refinement using a single mesh is considered, where the element order may differ for individual fields.FindingsIn coupled problems, the error in each single field is affected by approximation properties of all other field quantities. In order to allow for optimal convergence order in the number of degrees of freedom, the error contributions of all fields have to be considered. Separate error estimation in each field is needed especially inh‐adaptation on a single mesh. Energy coupling coefficients were introduced to derive an adaptation criterion. Convergence analysis ofh‐ andp‐adaptation proves the feasibility of the approach.Originality/valuePiezopyroelectricity considers thermal effects in high‐frequency piezoelectric materials, which is a coupled problem of four natures. The paper introduces an adaptation criterion for such complicated coupled problems and proves feasibility.
Comparison of pull‐in voltages in MEMS using 3D FEM and analytical approaches
Authors: Bölöni Francisc , Benabou Abdelkader , Tounzi Abdelmounaïm 
Published: December 2010

PurposeElectrostatic microelectromechanical systems are characterized by the pull‐in instability, associated to a pull‐in voltage. A good design requires an accurate model of this pull‐in phenomenon. The purpose of this paper is to present two approaches to building finite element method (FEM) based models.Design/methodology/approachClosed form expressions for the computation of the pull‐in voltage, can provide fast results within reliable accuracy, except when treating cases of extreme fringing fields. FEM‐based models come handy when high accuracy is needed. In the first model presented in this paper, the FEM is used to solve the electrostatic problem, while the mechanical problem is solved using a simplified Euler‐Bernoulli beam equation. The second model is a pure FEM model coupling the electrostatic and mechanical problems iteratively through the electrical force. Results for both scalar and vector potential formulations for the FEM models are presented.FindingsIn this paper a comparative study of simple pull‐in structures is presented, between analytical and 3D FEM‐based models. A comparison with analytical models and experimental results is also realized.Research limitations/implicationsThe coupling between the electrostatic and mechanical problem in the presented approaches, is iterative. Therefore, to improve the accuracy of the presented model, a strong coupling is needed.Originality/valueIn the presented FEM‐analytical model, the electrostatic problem is solved in both, scalar and vector electric potential formulations. This allows defining an upper and a lower limit for the electrostatic force and consequently for the pull‐in voltage.
Selecting and implementing a patron‐driven resource reservation system
Authors: Sallans Andrew , Soule Kathryn , Gilbert Joseph 
Published: December 2010

PurposeThe purpose of this paper is to describe criteria for selecting and processes for implementing a self‐service online resource reservation using the University of Virginia (U.Va.) Library as a case study.Design/methodology/approachThe paper chronicles the identified needs, selection criteria, and deployment strategy undertaken by a U.Va. Library task force in early to mid‐2010 along with the unexpected pitfalls and policy implications uncovered by the process.FindingsThe U.Va. Library selected and rolled out a product meeting a variety of public service needs, EMS Enterprise, in the summer/fall of 2010, with lessons learned about the intricacies of IT infrastructure, public service policies and procedures, and the varied resource reservation needs of the library's libraries and labs.Originality/valueThe paper demonstrates how the addition of a self‐scheduling reservation system has helped fill a long‐awaited need and adds value to the U.Va. Library's Services.
Link analysis and impact of top universities of Islamic world on the world wide web
Authors: Didegah Fereshteh , Goltaji Marzieh 
Published: December 2010

PurposeThis purpose of this paper is to report on an analysis of linkages and impact of top universities of Islamic Countries on the web.Design/methodology/approachThe AltaVista search engine was used to calculate universities' number of links and web impact factors.FindingsThe results revealed that half of the universities have not scored well in the indexes used by the webometrics ranking model. Among all universities, King Saud University of Saudi Arabia scored well in most indexes.Originality/valueThe paper presents a look at the functions and performance of top universities' web sites of Islamic countries.
A comparative study of two different techniques for evaluating service quality
Authors: Gupta Sumana , Nath Datta Rabindra 
Published: December 2010

PurposeThe conventional methods of evaluating service quality analyze data obtained in ordinal scale that assumes scale continuum. The purpose of this paper is to compare the control boundary model with a proposed method that uses law of categorical judgment, which converts data into interval scale. In this paper, the advantages of using the law of categorical judgment over the control boundary model, a method which uses the data directly, is presented by analyzing customer response data obtained to evaluate quality of service in the Howrah Railway Station, a major railway terminal in eastern India.Design/methodology/approachLaw of categorical judgment has been used for data conversion to interval scale and a comparative analysis is made with the results obtained from control boundary model.FindingsThe results obtained from the two techniques show that the proposed method of evaluation is more suitable to the context.Research limitations/implicationsThe work is limited to the subjective evaluation of the physical and functional services of a railway station. Several other aspects like managerial, behavioral, etc. are not considered.Originality/valueEvaluating service quality in this domain is a difficult task. The paper not only proposes a new method but also compares the results with an existing evaluation model.
A note on corporate social responsibility (CSR) in city branding and design
Authors: Kim Jai B. , Kwak Gretta , Koo Yoo R. 
Published: December 2010

PurposeBy exploring the evolution of corporate social responsibility (CSR) and evaluating major frameworks of CSR provided in a wider range of early works, this paper attempts to identify key domains of CSR and propose the revised CSR framework for strategic CSR management processes. The paper provides extended insights into how the concept of strategic CSR is integrated into city branding and design and highlights and addresses the roles of CSR that are inter‐linked to city brand management in terms of sustainable value creation to meet a community's societal, political or economic objectives.Design/methodology/approachThe overall content of this paper is concerned with theory of CSR and the fundamental logic behind city branding. The frameworks are developed based upon the historical review of theory and observation of trends in the current issues.FindingsThe paper funds that CSR is an integral framework to encompass not just principles of social responsibility, but processes of social responsiveness and outcomes of social performance as well.Research limitations/implicationsNotwithstanding a number of management literature that seeks out strategic linkages between competitive advantage, a crucial strategy concept and CSR, research concerned with the relationship between CSR and city branding is at in its infancy. There is a need to examine the essential ingredients that produce design‐driven value in the process of implementing strategic CSR into city branding. Future research, taking the difference between the firm/product and the city into account, will further investigate how city branding and design can be implemented to reflect social responsibility, notably in terms of the process and evaluation.Originality/valueThe paper not only presents the revised framework of CSR and major constituents of strategic CSR but also seeks to enlighten and establish a new connection between CSR and value creation that bring us an innovative perspective when implemented in city branding and design.
A study of the factors which influence franchisor profit structure with running royalty policy for its sustainable growth
Authors: Kwon Tae‐Woo(Mike) , Choi Kanghwa 
Published: December 2010

PurposeThe purpose of this paper is to assess the conceptual relationship between the running royalty programs and the performance of a franchisee or franchisor. Thus, this paper will analyze the correlation of financial stability when the franchisor strengthens the running royalty policy at aspect of franchisor.Design/methodology/approachA model is presented and designed. The paper will analyze the causality which is affected by strengthening the profit structure with the running royalty program and also find out how the strengthened profit structure will affect and improve the franchisors' sustainable supports for the franchisees, service quality and service satisfactions.FindingsAlthough the franchise industry is growing in Korea, the stability of business is still in doubt because the business cycle of the franchisor is shortened. This paper found the reasons why franchisors have unstable status in Korea. The main reason was the instability of profit structures for franchisors which are a burden to the franchisees which then worsen the franchisors' financial status. The biggest different from the US franchise industry was the running royalty program. So, this paper will apply the running royalty program politically to the franchise business in Korea and find out how it will affect the overall business cycle.Originality/valueThis study was limited to the Korean franchise industry and found out the factors which influence the franchisors' performance in various aspects. By analyzing with casual loop diagram, this paper found how each of the factors interact and bring out the positive feedback process. Also, it suggests a way of adopting the running royalty program into the Korean market.
Economic‐statistical design of variable sampling intervals EWMA charts under non‐normality
Authors: Xue Li , Xu Jichao , Liu Yumin 
Published: December 2010

PurposeThe purpose of this paper is to investigate the economic‐statistical design of EWMA charts with variable sampling intervals (VSIs) under non‐normality to reduce the process production cycle cost and improve the statistical performance of control charts. The objective is to minimize the cost function by adjusting the control chart parameters which suffice for the statistical restriction.Design/methodology/approachFirst, using the Burr distribution to approximate various non‐normal distributions, the economic‐statistical model of the VSI EWMA charts under non‐normality can be developed. Further, the genetic algorithms will be used to search for the optimal values of parameters of the VSI EWMA charts under non‐normality. Finally, a sensitivity analysis is carried out to investigate the effect of model parameters and statistical restriction on the solution of the economic‐statistical design.FindingsThe result of sensitivity analysis shows that a large lower bound of average time to signal when the process is in control increases the control limit coefficient, no model parameter significantly affects the short sampling intervals, and so on.Originality/valueThe economic‐statistical design method proposed in this paper can improve the statistical performance of economic design of control charts and the general idea can be applied to other VSI control charts.
An empirical model to assess the influence of the government's research and development program on Korean small and medium enterprise (SME) performance
Authors: Young Park Ji , Wook Kim Soo 
Published: December 2010

PurposeThe purpose of this paper is to suggest an empirical model to assess the separate effect of the government's research and development (R&D) policy program in small and medium enterprise (SME) performance.Design/methodology/approachThe paper reviews the R&D related papers and finds out the specific aspects of the Korean R&D policy program, classifying every R&D policy program and giving them unique names such as funds, technology and human resource support. Finally, the paper provides the whole empirical model and research questions for future studies.FindingsFirst, the paper suggests the research model and several questions about whether the direct government funding of R&D policy program has had an effect on SMEs' business performance. Second, the interaction of direct government R&D funding, technology and human resource support are compared. Finally, a research model is suggested with proper research methodology.Research limitations/implicationsOwing to the research purpose, the paper ends with the suggestion of an empirical model. Panel data needs to be applied to verify the suggested model.Originality/valueThere are various papers regarding the effect of R&D investment from private and public sectors, but few papers exist about the causal relationship between the government R&D policy program and SMEs' performance.
Plasma levels of glucagon like peptide‐1 associate with diastolic function in elderly men
Authors: Nathanson D. , Zethelius B. , Berne C. , Lind L. , Andrén B. , Ingelsson E. , Holst J. J. , Nyström T. 
Published: December 2010

Diabet. Med. 28, 301–305 (2011)AbstractAims  Congestive heart failure is a major cause of morbidity and mortality in diabetes. Besides the glycaemic effects of glucagon‐like peptide 1 (GLP‐1) mimetics, their effects on the heart are of interest.Methods  We aimed to investigate longitudinal relationships between plasma levels of fasting GLP‐1 (fGLP‐1), 60‐min oral glucose tolerance test‐stimulated GLP‐1 levels (60GLP‐1), and the dynamic GLP‐1 response after oral glucose tolerance test (ΔGLP‐1 = 60GLP‐1 – fGLP‐1) and incidence of hospitalized congestive heart failure, during a follow‐up time of a maximum of 9.8 years in 71‐year‐old men. We also investigated, cross‐sectionally, the association between GLP‐1 and left ventricular function as estimated by echocardiography.Results  During the follow‐up period, 16 of 290 participants with normal glucose tolerance experienced a congestive heart failure event (rate 0.7/100 person‐years at risk), as did eight of 136 participants (rate 0.8/100 person‐years at risk) with impaired glucose tolerance and nine of 72 participants (rate 1.7/100 person‐years at risk) with Type 2 diabetes mellitus. Although GLP‐1 concentrations did not predict congestive heart failure (fGLP‐1: HR 0.98, 95% CI 0.4–2.4; 60GLP‐1: HR 1.1, 95% CI 0.4–2.6; ΔGLP‐1: HR 0.9, 95% CI 0.3–2.3), there was an association between left ventricular diastolic function (E/A ratio) and fGLP‐1 (r = 0.19, P = 0.001), 60GLP‐1 (r = 0.20, P < 0.001) and ΔGLP‐1 (r = 0.18, P = 0.004). There was a lack of differences in plasma levels of GLP‐1 between the groups with Type 2 diabetes and normal glucose tolerance.Conclusions  There were no longitudinal associations between GLP‐1 levels and incidence of hospitalization for congestive heart failure. However, without any causality proven, GLP‐1 levels did correlate, cross‐sectionally, with left ventricular diastolic function in this cohort, suggesting that pathways including GLP‐1 might be involved in the regulation of cardiac diastolic function.
Exercise treadmill testing in patients with claudication, with and without diabetes
Authors: Mahé G. , Ouedraogo N. , Leftheriotis G. , Vielle B. , Picquet J. , Abraham P. 
Published: December 2010

Diabet. Med. 28, 356–362 (2011)AbstractAim  To compare symptoms and walking capacities of patients with and without diabetes reporting vascular‐type claudication.Methods  We recorded self‐reported maximal walking distance, maximal walking distance on treadmill test (3.2 km h−1, 10% slope), exercise transcutaneous oxygen pressure DROP index [limb transcutaneous oxygen pressure (TcpO2) changes from rest minus chest TcpO2 changes from rest] and symptoms on treadmill in 230 patients with diabetes and 982 patients without diabetes. Exercise‐induced proximal and distal symptoms were analysed in the perspective of underlying proximal and distal ischaemia (DROP value < negative 15 mmHg).Results  Self‐reported maximal walking distance did not differ between groups, whereas maximal walking distance on treadmill test was lower in patients with diabetes vs. patients without diabetes (261 ± 257 and 339 ± 326 m, respectively; P < 0.05 when adjusted for potential confounders). In patients with ischaemia, the number of ischaemic areas (proximal and/or distal on right and/or left) was comparable between the two groups. Patients with diabetes had more distal ischaemia than patients without diabetes (38 vs. 29%, respectively; P < 0.01), whereas proximal ischaemia was similar between groups. The prevalence of lower‐limb exercise‐related symptoms without ischaemia was comparable between groups. There were more symptoms other than lower‐limb pain in patients with diabetes than patients without diabetes (29.6 vs. 18.3%, respectively; P < 0.01).Conclusions  Patients with diabetes show more severe limitation on the treadmill and more non‐limb symptoms than patients without diabetes, although self‐reported walking capacity is comparable between the two groups. Using TcpO2, we confirm that patients with diabetes reporting claudication show more distal ischaemia than patients without diabetes, with no difference at the buttock level. Treadmill testing is of interest in patients with peripheral artery disease and diabetes.