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Two transmission line meshes to simulate electromagnetic waves in the Earth's atmosphere are developed, one with the link transmission lines connected in parallel and the other with connections in series.

The equations describing propagation of waves through these parallel or series meshes are equivalent to the Maxwell equations for TE^r or TM^r modes in a spherical cavity with lossy dielectric material between the external conducting surfaces, respectively.

The transmission line meshes are used for a numerical study of the natural electromagnetic noise due to lightning discharges in the Earth‐ionosphere cavity.

The numerical algorithm finds values for Schumann resonances very close to the experimental ones, which allows us to affirm that this methodology is a valid numerical tool for predicting these resonances on other planets or moons as well.

The purpose of this paper is to consider whether those nonprofit organizations which exhibit more similar characteristics to market organizations regarding the percentage of paid employees with functions similar to the ones in market organizations in relationship with total workers have a different model of human resource management in relation to their CEO than those organizations which exhibit fewer similarities to market organizations.

The hypotheses proposed in this study have been tested using a sample of 1,999 Spanish nonprofit organizations.

The results show that the CEOs of nonprofit organizations with most similarity to for‐profit organizations will have a more formalized employment relationship and a higher level of education than the CEOs of nonprofits with least similarity to for‐profit organizations.

This paper has several limitations from the heterogeneity of the sample to the fact that the conducted study is a cross‐sectional study of the current situation.

The practical implications of this paper imply that nonprofit organizations which are evolving, in terms of their workforce, towards a high percentage of paid employees or those who are already in this position will have to adapt to the way in which for‐profit organizations operate if they wish to achieve levels of effectiveness and efficiency to make them competitive in this sector.

One of the reasons for proposing this work is the small number of empirical studies trying to address systematically the relationship between the CEO and the characteristics of nonprofit organizations.

The purpose of this paper is to propose an interpretation of the grey relational grade taking into account its variation range on the basis of the error propagation theory.

The paper uses error propagation theory to calculate the uncertainty of the grey relational grade, exploring how errors are propagated through the sequential operations of the grey relational analysis.

The non‐consideration of the error associated to the measurement of the experimental data that is transferred to the grey relational grade may have a potential effect on the interpretation of the grey relational rank. Data uncertainty quantification provides information about how well measurement fits to the value of the measured quantity and determines its validity. Therefore, this might lead one to consider that some sequences are less attractive than other lower‐ranked ones.

The combination of the grey and error propagation theories is a tool to choose the most accurate solution in grey relational grade ranks.

This study provides a new approach to interpret grey relational grade classifications.

The purpose of this paper is to introduce the anniversary issue marking 30 years of academic publication.

This anniversary issue contains 12 articles from 11 countries and 17 academic institutions which present literature reviews, meta-analyses, and novel studies. It also contains testimonials about the history of the journal from Enrique Ogliastri (Editor and/or Director between 1998 and 2018), Elvira Salgado (Editor between 2002 and 2013), and Carlos Pombo (Chief Editor, 2013 to the present).

The history of the journal may be divided into five stages: first, the foundation at the Universidad de Chile (1988-1998); second, the move to the Universidad de los Andes (Bogotá) and the preparation of a proposal to the Institute of Scientific Information (ISI) for inclusion among the scientific journals of the world (1999-2004); third, a period of consolidation in Latin America (2004-2007); fourth, the acceptance of the journal in ISI and the development of an electronic platform with free access to the journal (2008-2013); and fifth, the entry of the Emerald group as editorial partner (2013-2018).

The 12 articles present literature reviews, meta-analyzes, and novel studies.

El propósito de este editorial es presentar el tema del aniversario.

Se publican doce artículos provenientes de once países y 17 instituciones académicas. Se presentan los testimonios de Enrique Ogliastri (editor y/o director entre 1998 y 2018), Elvira Salgado (Editora entre 2002 y 2013), y Carlos Pombo (jefe editorial 2013-2018).

Se publican doce artículos provenientes de once países y 17 instituciones académicas. Se presentan los testimonios de Enrique Ogliastri (editor y/o director entre 1998 y 2018), Elvira Salgado (Editora entre 2002 y 2013), y Carlos Pombo (jefe editorial 2013-2018). La historia de la revista de CLADEA se podría dividir en cinco etapas: la fundación en la Universidad de Chile (1988-1998); pasó a cargo de la Universidad de los Andes (Bogotá), un período de puesta a punto para presentar al Institute of Scientific Information (ISI) la solicitud de ser analizada e incluida entre las revistas científicas del mundo (1999-2004); el período de consolidación en América Latina (2004-2007); la aceptación en ISI y el desarrollo de una plataforma electrónica de acceso libre a la revista (2008-2013); y el ingreso del grupo Emerald como socio editorial (2013-2018).

Los 12 artículos presentan revisiones de literatura, metanálisis y estudios novedosos

The purpose of this paper is to describe the obsolescence process of Microsoft Academic Search (MAS) as well as the effects of this decline in the coverage of disciplines and journals, and their influence in the representativeness of organizations.

The total number of records and those belonging to the most reputable journals (1,762) and organizations (346) according to the Field Rating indicator in each of the 15 fields and 204 sub-fields of MAS, have been collected and statistically analysed in March 2014, by means of an automated querying process via http, covering academic publications from 1700 to present.

MAS has no longer been updated since 2013, although this phenomenon began to be glimpsed in 2011, when its coverage plummeted. Throughout 2014, indexing of new records is still ongoing, but at a minimum rate, without following any apparent pattern.

There are also retrospective records being indexed at present. In this sense, this research provides a picture of what MAS offered during March 2014 being queried directly via http.

The unnoticed obsolescence of MAS affects to the quality of the service offered to its users (both those who engage in scientific information seeking and also those who use it for quantitative purposes).

The predominance of Google Scholar (GS) as monopoly in the academic search engines market as well as the prevalence of an open construction model (GS) vs a closed model (MAS).

A complete longitudinal analysis of disciplines, journals and organizations on MAS has been performed for the first time identifying an unnoticed obsolescence. Any public explanation or disclaimer note has been announced from the responsible company, something incomprehensible given its implications for the reliability and validity of bibliometric data provided on disciplines, journals, authors and congress as well as their fair representation on the academic search engine.

Google Scholar Citations (GSC) provides an institutional affiliation link which groups together authors who belong to the same institution. The purpose of this paper is to ascertain whether this feature is able to identify and normalize all the institutions entered by the authors, and whether it is able to assign all researchers to their own institution correctly.

Systematic queries to GSC’s internal search box were performed under two different forms (institution name and institutional e-mail web domain) in September 2015. The whole Spanish academic system (82 institutions) was used as a test. Additionally, specific searches to companies (Google) and world-class universities were performed to identify and classify potential errors in the functioning of the feature.

Although the affiliation tool works well for most institutions, it is unable to detect all existing institutions in the database, and it is not always able to create a unique standardized entry for each institution. Additionally, it also fails to group all the authors who belong to the same institution. A wide variety of errors have been identified and classified.

Even though the analyzed sample is good enough to empirically answer the research questions initially proposed, a more comprehensive study should be performed to calibrate the real volume of the errors.

The discovered affiliation link errors prevent institutions from being able to access the profiles of all their respective authors using the institutions lists offered by GSC. Additionally, it introduces a shortcoming in the navigation features of Google Scholar which may impair web user experience.

Some institutions (mainly universities) are under-represented in the affiliation feature provided by GSC. This fact might jeopardize the visibility of institutions as well as the use of this feature in bibliometric or webometric analyses.

This work proves inconsistencies in the affiliation feature provided by GSC. A whole national university system is systematically analyzed and several queries have been used to reveal errors in its functioning. The completeness of the errors identified and the empirical data examined are the most exhaustive to date regarding this topic. Finally, some recommendations about how to correctly fill in the affiliation data (both for authors and institutions) and how to improve this feature are provided as well.

The purpose of this paper is to capture the actual structural behavior of the longest timber footbridge in Spain by means of a multi-scale model updating approach in conjunction with ambient vibration tests.

In a first stage, a numerical pre-test analysis of the full bridge is performed, using standard beam-type finite elements with isotropic material properties. This approach offers a first structural model in which optimal sensor placement (OSP) methodologies are applied to improve the system identification process. In particular, the effective independence (EFI) method is used to determine the optimal locations of a set of sensors. Ambient vibration tests are conducted to determine experimentally the modal characteristics of the structure. The identified modal parameters are compared with those values obtained from this preliminary model. To improve the accuracy of the numerical predictions, the material response is modeled by means of a homogenization-based multi-scale computational approach. In a second stage, the structure is modeled by means of three-dimensional solid elements with the above material definition, capturing realistically the full orthotropic mechanical properties of wood. A genetic algorithm (GA) technique is adopted to calibrate the micromechanical parameters which are either not well-known or susceptible to considerable variations when measured experimentally.

An overall good agreement is found between the results of the updated numerical simulations and the corresponding experimental measurements. The longitudinal and transverse Young's moduli, sliding and rolling shear moduli, density and natural frequencies are computed by the present approach. The obtained results reveal the potential predictive capabilities of the present GA/multi-scale/experimental approach to capture accurately the actual behavior of complex materials and structures.

The uniqueness and importance of this structure leads to an intensive study of its structural behavior. Ambient vibration tests are carried out under environmental excitation. Extraction of modal parameters is obtained from output-only experimental data. The EFI methodology is applied for the OSP on a large-scale structure. Information coming from several length scales, from sub-micrometer dimensions to macroscopic scales, is included in the material definition. The strong differences found between the stiffness along the longitudinal and transverse directions of wood lumbers are incorporated in the structural model. A multi-scale model updating approach is carried out by means of a GA technique to calibrate the micromechanical parameters which are either not well-known or susceptible to considerable variations when measured experimentally.

It is common for an international company to have different brands, products or services, information for investors, a corporate blog, affiliates, branches in different countries, etc. If all these contents appear as independent additional web domains (AWDs), the company should be represented on the web by all these web domains, since many of these AWDs may acquire remarkable performance that could mask or distort the real web performance of the company, affecting therefore on the understanding of web metrics. The purpose of this paper is to determine the amount, type, web impact and topology of the AWDs in commercial companies in order to get a better understanding on their complete web impact and structure.

The set of companies belonging to the Spanish IBEX-35 stock index has been analysed as testing bench. The authors proceeded to identify and categorise all AWDs belonging to these companies, and to apply both web impact (web presence and visibility) and network metrics.

The results show that AWDs get a high web presence but relatively low web visibility, due to certain opacity or less dissemination of some AWDs favoring its isolation. This is verified by the low network density values obtained, that occur because AWDs are strongly connected with the corporate domain (although asymmetrically), but very weakly linked each other.

The categories used to classify the various AWD, although they are clearly distinguishable conceptually, have certain limitations in practice, since they depend on the form adopted by companies to publish certain content or to provide certain services or products. Otherwise, the use of web indicators presents certain problems of accuracy that could be softened if applied with caution and in a relational basis.

Although the processes of AWDs creation and categorisation are complex (web policy seems not to be driven by a defined or conscious plan), their influence on the web performance of IBEX 35 companies is meaningful. This research measures the AWDs influence on companies under webometric terms for the first time.

This study aims to examine the full mediating role of supply chain flexibility (SCF) between lean production (LP) and business performance (BP) found in the previous literature. This effect negates the direct LP-BP effect (the so-called “total eclipse effect”). The authors analyze the individual contributions that the different SCF dimensions (sourcing flexibility; operating system flexibility, distribution flexibility and information system [IS] flexibility) make to the “total eclipse effect” between LP and BP produced by SCF. The relational resources-based view and resource orchestration theory are used to support the theoretical framework.

Covariance-based structural equations modeling (CB-SEM) is used to test the SCF LP-BP total eclipse hypothesis and four additional mediation hypotheses, one for each of the SCF dimensions. Data obtained via a questionnaire given to 260 companies are analyzed with CB-SEM, and SPSS Process is used to evaluate the mediation effect.

Research results indicate that only one of the dimensions (operating system flexibility) has a full mediation effect between LP and BP and is, therefore, the main contributor to the eclipse effect. Two other dimensions (sourcing flexibility and distribution flexibility) have partial mediation effects, so they also contribute to developing the eclipse effect, although to a lesser extent. Finally, IS flexibility is neither a full nor a partial mediation factor and does not contribute to the eclipse effect.

These findings have some important implications. For academia, they generate new knowledge of the role that each of the SCF dimensions or components plays in the LP-BP relationship. For company management, the findings offer supply chain managers specific information on the individual effects that the different types of SCF flexibility have between LP and BP. This will allow companies to target their efforts to develop certain types of flexibility in LP contexts depending on the outcomes that senior managers want to achieve with their SCs.