Same data—different results? Towards a comparative approach to the identification of thematic structures in science

Science studies are persistently challenged by the elusive structures of their subject matter, be it scientific knowledge or the various collectivities of researchers engaged with its production. Bibliometrics has responded by developing a strong and growing structural bibliometrics, which is concerned with delineating fields and identifying thematic structures. In the course of these developments, a concern emerged and is steadily growing. Do the sets of publications, authors or institutions we identify and visualise with our methods indeed represent thematic structures? To what extent are results of topic identification exercises determined by properties of knowledge structures, and to what extent are they determined by the approaches we use? Do we produce more than artefacts? These questions triggered the collective process of comparative topic identification reported in this special issue. The introduction traces the history of bibliometric approaches to topic identification, identifies the major challenges involved in these exercises, and introduces the contributions to the special issue.     

Designing and building SDN testbeds for energy-aware traffic engineering services

As experimenting with energy-aware techniques on large-scale production infrastructure is prohibitive, a large number of proposed traffic engineering strategies have been evaluated only using discrete-event simulations. The present work discusses (i) challenges towards building testbeds that allow researchers and practitioners to validate and evaluate the performance and quality of energy-aware traffic engineering strategies, (ii) requirements to fulfil when porting simulations to testbeds, and (iii) two proof-of-concept testbeds. One testbed uses and provides software-defined network (SDN) services created on the open-network operating system while the other is a composition of virtual Open vSwitches controlled by the Ryu SDN framework. The aim of the testbeds is to validate previously proposed energy-aware traffic engineering strategies in different environments. We detail the platforms and illustrate how they have been used for performance evaluation. Additionally, the paper compares results obtained in the testbeds with evaluations performed using discrete-event simulations and presents challenges faced while implementing energy-aware traffic engineering mechanisms as SDN services in testbed environments.     

Cyclodextrins in polymer synthesis: Influence of methylated β-cyclodextrin as host on the free radical copolymerization reactivity ratios of hydrophobic acrylates as guest monomers in aqueous medium

Summary Methylated (β-cyclodextrin (me-β-CD) was used to complex the hydrophobic monomers n-butyl acrylate (1), n-hexyl acrylate (2) and cyclohexyl acrylate (3) yielding the corresponding water soluble host/guest complexes 1a–3a. The complexes were copolymerized in water by free radical mechanism and the reactivity ratios were determined by measuring the monomer consumption by HPLC. The following reactivity ratios were found: copolymerization of 1a and 2a: r₁= 1.01 ± 0.01; r₂= 1.04 ± 0.01; copolymerization of 3a and 2a: r₁= 0.74; r₂= 1.28; copolymerization of 3a and 1a: r₁= 0.75 ± 0.04; r₂= 1.13 ± 0.01. In contrast to that, the copolymerization of the uncomplexed monomers 1–3 in organic medium (DMF/H₂O) leads to nearly ideal statistical copolymers in all cases. Received: 28 November 2000/Accepted: 12 January 2001     

Publication and cooperation patterns of the authors of neuroscience journals

Characteristics of publication activity and co-authorship in neurosciences are analysed. The present study aims at describing the common, as well as the distinguishing features of productivity and co-publication patterns of four types of authors. For this purpose, authors are classified according to their anterior and posterior records. The role of the author types in the process of documented scientific communication, the relation between co-authorship and publication activity, as well as collaboration between the four types is studied. This revised version was published online in June 2006 with corrections to the Cover Date.     

Multiple-reason decision making based on automatic processing.

It has been repeatedly shown that in decisions under time constraints, individuals predominantly use noncompensatory strategies rather than complex compensatory ones. The authors argue that these findings might be due not to limitations of cognitive capacity but instead to limitations of information search imposed by the commonly used experimental tool Mouselab (J. W. Payne, J. R. Bettman, & E. J. Johnson, 1988). The authors tested this assumption in 3 experiments. In the 1st experiment, information was openly presented, whereas in the 2nd experiment, the standard Mouselab program was used under different time limits. The results indicate that individuals are able to compute weighted additive decision strategies extremely quickly if information search is not restricted by the experimental procedure. In a 3rd experiment, these results were replicated using more complex decision tasks, and the major alternative explanations that individuals use more complex heuristics or that they merely encode the constellation of cues were ruled out. In sum, the findings challenge the fundaments of bounded rationality and highlight the importance of automatic processes in decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A bibliometric analysis of international scientific cooperation of the European Union (1985–1995)

Scientific cooperation of the EU countries with other developed regions, with Economies in Transition and with Developing Countries is analysed as it is reflected in the bibliometric indicators of internationally co-authored publications. The citation attractivity of these publications shows that international scientific collaboration is particularly advantageous for less advanced countries, but also highly industrialised countries benefit from it.     

Domesticity and internationality in co-authorship,references and citations

Summary As a first element of a macro-level country-by-country cross-reference and cross-citation analysis, domestic/international character of reference and citation behavior of 36 countries is studied and compared with international co-authorship patterns. Indicators of reference and citation domesticity as well as reference-citation domesticity balance are constructed and presented. Science policy relevance of these indicators is discussed and examples deserving science policy attention are pinpointed.