Science is a societal process, designed on widely accepted general rules which facilitate its development. Productive researchers are viewed from the perspective of a social network of their interpersonal relations. In this paper we address performance of Slovenian research community using bibliographic networks between the years 1970 and 2015 from various aspects which determine prolific science. We focus on basic determinants of research performance including productivity, collaboration, internationality, and interdisciplinarity. For each of the determinants, we select a set of statistics and network measures to investigate the state of each in every year of the analyzed period. The analysis is based on high quality data from manually curated information systems. We interpret the results by relating them to important historical events impacting Slovenia and to domestic expenditure for research and development. Our results clearly demonstrate causal relations between the performance of research community and changes in wider society. Political and financial stability together with concise measuring of scientific productivity established soon after Slovenia won independence from Yugoslavia in 1991 had positive influence on all determinants. They were further leveraged by foundation of Slovenian research agency and joining EU and NATO. Publish and perish phenomenon, negative impacts of financial crisis in 2008-2014 and reshaping the domestic expenditure for research.
COBISS.SI-ID: 2048412691
Topologies of real-world complex networks are rarely accessible. However, they can sometimes be reconstructed from experimentally obtained time series. This call for improvement of network reconstruction methods. Extending our earlier work, here we present a new method built on integrating an evolutionary optimization algorithm into the derivative-variable correlation method. Results obtained from our modification of the method in general outperform the original results. We also show the method's usefulness in realistic scenarios.
COBISS.SI-ID: 2048462099
Simultaneous broadcasting of multiple messages from the same source vertex in synchronous networks is considered under restrictions that each vertex receives at most one message in a unit time step, every received message can be sent out only in the next time step, no message is sent to already informed vertices. The number of outgoing messages is unrestricted, messages have unit length, and we assume full-duplex mode. In Gregor et al. (2015), we developed a concept of level-disjoint partitions to study simultaneous broadcasting under this model. In this work, we consider the optimal number of level-disjoint partitions. We also provide a necessary condition in terms of eccentricity and girth on existence of k v-rooted level-disjoint partitions of optimal height. In particular, we provide a structural characterization of graphs admitting two level-disjoint partitions with the same root.
COBISS.SI-ID: 31040807
Living complex systems create functionalities by pairing up complementary processes, one to build and another to correct and clean the space for more building. When these processes are mutually exclusive, establishing a balance between them requires a phase flipping mechanism. For a simple neuronal network composed of neurons and synapses, we demonstrate that flipping between excited and resting phases gives rise to a statistical conservation law of synaptic strength. This law is selected by evolution regardless of the network’s initial state. This finding reconciles biology with the physical concept of self-organized criticality.
COBISS.SI-ID: 2048561683
In this paper we consider the question what is the scientific and career performance of principal investigators (PI's) of publicly funded research projects compared to scientific performance of all researchers. Our study is based on high quality data about (1) research projects awarded in Slovenia in the period 1994-2016 (7508 projects with 2725 PI's in total) and (2) about scientific productivity of all researchers in Slovenia that were active in the period 1970-2016 - there are 19,598 such researchers in total, including the PI's. We compare average productivity, collaboration, internationality and interdisciplinarity of PI's and of all active researchers. Our analysis shows that for all four indicators the average performance of PI's is much higher compared to average performance of all active researchers. Additionally, we analyze careers of both groups of researchers. The results show that the PI's have on average longer and more fruitful career compared to all active researchers, with regards to all career indicators. The PI's that have received a postdoc grant have at the beginning outstanding scientific performance, but later deviate towards average. On long run, the PI's leading the research programs (the most prestigious grants) on average demonstrate the best scientific performance.
COBISS.SI-ID: 33981657