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The electromagnetic properties of microwave transmission lines can be described using Maxwell’s equations in the frequency domain. Applying a finite‐volume scheme results in an algebraic eigenvalue problem. In this paper an improved numerical computation of the eigenmodes is presented. Avoids the time‐ and memory‐consuming computation of all eigenvalues in order to calculate a selected set of propagation constants using an iterative method that is carried out twice. The numerical effort and the storage requirements can be reduced considerably.

The design of microwave circuits requires detailed knowledge on the electromagnetic properties of the transmission lines used. This can be obtained by applying Maxwell’s equations to a longitudinally homogeneous waveguide structure, which results in an eigenvalue problem for the propagation constant. Special attention is paid to the so‐called perfectly matched layer boundary conditions (PML). Using the finite integration technique we get an algebraic formulation. The finite volume of the PML introduces additional modes that are not an intrinsic property of the waveguide. In the presence of losses or absorbing boundary conditions the matrix of the eigenvalue problem is complex. A method which avoids the computation of all eigenvalues is presented in an effort to find the few propagating modes one is interested in. This method is an extension of a solver presented by the authors in a previous paper which analyses the lossless case. Using mapping relations between the planes of eigenvalues and propagation constants a strip in the complex plane is determined containing the desired propagation constants and some that correspond to the PML modes. In an additional step the PML modes are eliminated.The numerical effort of the presented method is reduced considerably compared to a full calculation of all eigenvalues.

The Journal of Documentation does not normally publish papers on the classification, etc., of specific subjects. An exception has been made in this case, since most of the available examples of faceted classifications are in the field of science and technology and it is felt useful to publish an illustration of the use of this technique for a subject within the humanities. The techniques of faceted classification were applied to the fine arts in a scheme which was designed for use in a college library. Some problems of classifying the literature are discussed, together with the solutions adopted. An excerpt schedule with an alphabetical subject index and some classified examples are provided to illustrate the project.

The purpose of this paper is to show how the coverage of publications is represented in information services. Academic citation databases (Web of Science, Scopus, Google Scholar) and scientific social media (Mendeley, CiteULike, BibSonomy) were analyzed by applying a new method: the use of personal publication lists of scientists.

Personal publication lists of scientists of the field of information science were analyzed. All data were taken in collaboration with the scientists in order to guarantee complete publication lists.

The demonstrated calibration parameter shows the coverage of information services in the field of information science. None of the investigated databases reached a coverage of 100 percent. However Google Scholar covers a greater amount of publications than other academic citation databases and scientific social media.

Results were limited to the publications of scientists working at an information science department from 2003 to 2012 at German-speaking universities.

Scientists of the field of information science are encouraged to review their publication strategy in case of quality and quantity.

The paper confirms the usefulness of personal publication lists as a calibration parameter for measuring coverage of information services.

The purpose of this paper is to identify governmental social media use in cities with enhanced information and communications technology infrastructures (i.e. Informational World Cities) and high Internet penetration rates. Social media platforms are increasingly being used by governments to foster user interaction and it was investigated if social media platforms are valuable tools for reaching high numbers of citizens.

This paper is based on an iterative content and Web analysis from November 2012 till January 2013 and offers a comparison of different social media service types and the particular use.

This empirical investigation of 31 Informational World Cities provides an overview of social media services used for governmental purposes, of their popularity among governments and of their usage intensity in broadcasting information online. Even as cities in a globalized world become more similar, a variety in the use of social media by governments was detected, which is due to regional and cultural characteristics.

The findings are limited to calculable data, e.g. number of used social media accounts, posts and followers which were available through a content and Web analysis at the time of investigation.

A more detailed content analysis, as well as a more differentiated analysis of users, must be conducted in the future.

This paper is one of the first that presents a global comparison of governmental social media use of cities of the knowledge society and compares different social media platforms.

The article aims to give an overview of the history and the achieved status of information science in the German Democratic Republic (GDR) with an emphasis on the organisation of information science and practice in the GDR and on the theoretical foundations of information science.

Primarily, this article is based upon critical literature studies, especially German-language books and journal articles, but the empirical basis also includes some unpublished sources (e.g. letters from information scientists from the GDR).

There are interesting results concerning the roots of information science in cybernetics, philosophy and the practical area of documentation. The naming of this knowledge field as “informatics”, “informatics of science” or “information and documentation science” is partly very distinct from Western conceptions. We found different theoretical foundations for information science including the approaches of Bonitz, Engelbert, Koblitz and Groß and Fuchs-Kittowski. In the GDR, information science and information practice were centralised, but through the information system science and technology, they were consistently accessible at all levels of professional work. With German reunification, information practice and its institutions, as well as GDR’s information science efforts, disappeared.

The article gives hints on the importance on and the survival of some GDR approaches in contemporary information science, but those developments should be analysed in much more detail.

This is the first overview article on the state and entire development of information science in the GDR.

Many Web 2.0 services (including Library 2.0 catalogs) make use of folksonomies. The purpose of this paper is to cut off all tags in the long tail of a document‐specific tag distribution. The remaining tags at the beginning of a tag distribution are considered power tags and form a new, additional search option in information retrieval systems.

In a theoretical approach the paper discusses document‐specific tag distributions (power law and inverse‐logistic shape), the development of such distributions (Yule‐Simon process and shuffling theory) and introduces search tags (besides the well‐known index tags) as a possibility for generating tag distributions.

Search tags are compatible with broad and narrow folksonomies and with all knowledge organization systems (e.g. classification systems and thesauri), while index tags are only applicable in broad folksonomies. Based on these findings, the paper presents a sketch of an algorithm for mining and processing power tags in information retrieval systems.

This conceptual approach is in need of empirical evaluation in a concrete retrieval system.

Power tags are a new search option for retrieval systems to limit the amount of hits.

The paper introduces power tags as a means for enhancing the precision of search results in information retrieval systems that apply folksonomies, e.g. catalogs in Library 2.0 environments.

The object of this empirical research study is emotion, as depicted and aroused in videos. This paper seeks to answer the questions: Are users able to index such emotions consistently? Are the users' votes usable for emotional video retrieval?

The authors worked with a controlled vocabulary for nine basic emotions (love, happiness, fun, surprise, desire, sadness, anger, disgust and fear), a slide control for adjusting the emotions' intensity, and the approach of broad folksonomies. Different users tagged the same videos. The test persons had the task of indexing the emotions of 20 videos (reprocessed clips from YouTube). The authors distinguished between emotions which were depicted in the video and those that were evoked in the user. Data were received from 776 participants and a total of 279,360 slide control values were analyzed.

The consistency of the users' votes is very high; the tag distributions for the particular videos' emotions are stable. The final shape of the distributions will be reached by the tagging activities of only very few users (less than 100). By applying the approach of power tags it is possible to separate the pivotal emotions of every document – if indeed there is any feeling at all.

This paper is one of the first steps in the new research area of emotional information retrieval (EmIR). To the authors' knowledge, it is the first research project into the collective indexing of emotions in videos.

This second of three articles by Bolko von Oetinger, a senior vice president and director of the Strategy Institute for the Boston Consulting Group, continues the distillation of ideas in the book, A Passion for Ideas: How Innovators Create the New and Shape Our World, edited by Heinrich von Pierer and von Oetinger (Purdue University Press, 2002). The book includes interviews with, and articles by successful innovators from many areas: business, politics, the arts, the sciences, psychology, education, advertising, architecture, universities, and schools. von Oetinger has blended comments from the experts with his own experience to offer five patterns of behavior needed for corporate innovation. This article provides many quotations from the book while presenting the third behavioral pattern: since our rules limit our actions, we have to break our own rules.