This paper examines the collaboration structures and dynamics of the co-authorship network of all Slovenian researchers. Its goal is to identify the key factors driving collaboration and the main differences in collaboration behavior across scientific fields and disciplines. Two approaches to modelling network dynamics are combined in this paper: the small-world model and the mechanism of preferential attachment, also known as the process of cumulative advantage. Stochastic-actor-based modelling of co-authorship network dynamics uses data for the complete longitudinal co-authorship networks for the entire Slovenian scientific community from 1996 to 2010. We confirmed the presence of clustering in all fields and disciplines. Preferential attachment is far more complex than a single global mechanism. There were two clear distinctions regarding collaboration within scientific fields and disciplines. One was that some fields had an internal national saturation inhibiting further collaboration. The second concerned the differential impact of collaboration with scientists from abroad on domestic collaboration. In the natural, technical, medical, and biotechnical sciences, this promotes collaboration within the Slovenian scientific community while in the social sciences and humanities this inhibits internal collaboration.
COBISS.SI-ID: 33292637
We explore classifying scientific disciplines including their temporal features by focusing on their collaboration structures over time. Bibliometric data for Slovenian researchers registered at the Slovenian Research Agency were used. These data were obtained from the Slovenian National Current Research Information System. We applied a recently developed hierarchical clustering procedure for symbolic data to the coauthorship structure of scientific disciplines. To track temporal changes, we divided data for the period 1986-2010 into five 5-year time periods. The clusters of disciplines for the Slovene science system revealed 5 clusters of scientific disciplines that, in large measure, correspond with the official national classification of sciences. However, there were also some significant differences pointing to the need for a dynamic classification system of sciences to better characterize them. Implications stemming from these results, especially with regard to classifying scientific disciplines, understanding the collaborative structure of science, and research and development policies, are discussed.
COBISS.SI-ID: 32693853
In the paper the theory of imprecise Markov chains is generalised from discrete to continuous time. This is achieved by a generalisation of Kolmogorov's backward equation into the form of a generalised differential equation. The distributions of the chain over the set of states as non-linear functionals are then bounded by the minimal and maximal solutions of these equations. Since they cannot be expressed in an analytical form, numerical methods for their computations are needed. We propose an innovative method that is computationally much more efficient than the ordinary discretisation methods, which are computationally very expensive.
COBISS.SI-ID: 33283165
We use balance theoretic ideas to study the dynamics of the international system of nations in a network of signed relations from 1946 through 1999. Using the Correlates of War data for this period, we apply pre-specified signed blockmodeling to characterize the fundamental structure of this network. Even though the system expanded greatly with many ties being created and/or destroyed, the basic structure remained the same but with new positions being added over time. The blockmodels generated temporal measures of imbalance, as did the counts of imbalanced triples. Regardless of using the line index of imbalance or the number of imbalanced 3-cycles, the results provided decisive evidence contradicting the balance theoretic hypothesis of signed networks moving towards balanced states. Structural balance theory remains very useful by pointing to the more important study of how and why signed networks move towards and away from balance at different points over time. Some major methodological problems for studying signed networks, regardless of whether they involve nations or human actors, were raised and addressed. Proposals for future research are suggested for modeling and understanding the dynamics of signed networks.
COBISS.SI-ID: 33384541
This article addresses the development of Qualitative Comparative Analysis (QCA) from its launching in 1987 until present. We surveyed from the perspective of QCA's proclaimed "case-orientedness". We started by examining the foundations of QCA and the way those foundations have evolved over three decennia, in particular in terms of the connection with case-oriented work. Furthermore, we demonstrate that this was and is still an important facet of QCA both as an approach and as a set of techniques. Additionally, in more concrete terms, we go through all the practical QCA operations and demonstrate that virtually in every step of the QCA procedure; there is a potential dialogue with the individual cases, whether they are defined at the macro-, meso- or micro levels. Finally, we analyze the current state of affairs which seems to run against the articulation between "deep" (in particular ethnographic) case-oriented work and QCA, and propose avenues to engage more thoroughly in deeper case-informed QCA work.
COBISS.SI-ID: 33784157