Variants of finite full transformation semigroups

The variant of a semigroup S with respect to an element a in S, denoted S^a, is the semigroup with underlying set S and operation * defined by x*y=xay for x,y in S. In this article, we study variants T_X^a of the full transformation semigroup T_X on a finite set X. We explore the structure of T_X^a as well as its subsemigroups Reg(T_X^a) (consisting of all regular elements) and E_X^a (consisting of all products of idempotents), and the ideals of Reg(T_X^a). Among other results, we calculate the rank and idempotent rank (if applicable) of each semigroup, and (where possible) the number of (idempotent) generating sets of the minimal possible size.Comment: 25 pages, 6 figures, 1 table - v2 includes a couple more references - v3 changes according to referee comments (to appear in IJAC

Impact of Membrane Computing and P Systems in ISI WoS. Celebrating the 65th Birthday of Gheorghe Păun

Membrane Computing is a branch of Computer Science initiated by Gheorghe Păun in 1998, in a technical report of Turku Centre for Computer Science published as a journal paper ("Computing with Membranes" in Journal of Computer and System Sciences) in 2000. Membrane systems, as Gheorghe Păun called the models he has introduced, are known nowadays as "P Systems" (with the letter P coming from the initial of the name of this research area "father"). This note is an overview of the impact in ISI WoS of Gheorghe Păun’s works, focused on Membrane Computing and P Systems field, on the occasion of his 65th birthday anniversary

Two lectures about representing scientific communities by data visualization

These lectures present a research that investigates the representation of communities, and the way to foster their understanding by different audiences. Communities are complex multidimensional entities intrinsically difficult to represent synthetically. The way to represent them is likely to differ depending on the audience considered: governing entities trying to make decision for the future of the community, general public trying to understand the nature of the community and the members of the community themselves. This work considers two types of communities as example: a scientific organization and an arising domain: the EPFL institutional community composed of faculty members and researchers and, at a world wide level, the emerging community of Digital Humanities researchers. For both cases, the research is organised as a process going from graphical research to actual materialization as physical artefacts (posters, maps, etc.), possibly extended using digital devices (augmented reality applications). Through iterative cycles of design and experimentation, the research explores theoretically (representation theory, studies about networks, cartography, etc.) and experimentally (development of methods to assess the relevance of each representation depending on the target audiences) how to create effective community mapping. Its global ambition is to inform a theory of design helping to understand how certain community representations can lead to actual cognitive shifts in the way a community is understood. First Day - Design Creation The lecture proposes a new way to look at scientific communities. Dealing with a very complex situation, where literacy production is enormous and decisions are made using metrics that are judged obsolete by all, we propose a visual way to understand the community organization. How do scholars work together? What is the intermediary object which makes scientific researchers work together? This first session transforms the current situation into a visual object, a design artefact that embodies the elemental in the creation of maps to understand and evaluate scientific communities. Second Day - Use of the Maps The lecture proposes the use of maps to understand and evaluate scientific communities. As continuation of yesterday's lecture, the topic of the day is how to present elementary objects—which represents publications, teaching, grants and subjects of matters—in a map. Several maps will be shown, representing a precise scientific community inside the EPFL, but with the perspective to make them adaptable to other communities. Moreover, much attention will be dedicated to the reading and interpretation of these maps. Finally a web-based software will be introduced, to illustrate to members and managers of any given community the benefit of a visual representation of a scientific organisation.</p

The multilayered identity of Tristan Tzara and Marcel Janco – the archives of an identity issue

This research focuses on the question of Jewish identity in Romania around the turn of the twentieth century, in the cases of Romanian-born Jews, Tristan Tzara and Marcel Janco. It argues that it was neither Tzara’s and Janco’s Jewish heritage, nor their connection to Jewish culture, that defined their artistic personalities, but a web of interrelated social, political and personal components, all part of their multilayered identity, of which their Jewishness was only one. In Romania, Jews have been variously stereotyped which led to a specific Jewish experience; simultaneously, and paradoxically, Eastern European Jews symbolized backwardness in the eyes of Western Jews. Taking these formulations as a starting point, the concern of this research is with the phenomenon of self-definition, and particularly with Tzara’s and Janco’s self-definition over against Romanian reality and its clichéd views on national identity and citizenship. By examining how the instability of national and ethnic identities in this part of Europe was manifested in their ‘Jewish experiences’, this research shows how the lack of national citizenship impacted their mindset at least the same way that their own Jewishness did, for it only accentuated their marginalisation. By drawing on archival sources and sociological knowledge, this research makes novel use of the Deleuzoguattarian concept of becoming to discuss how Tzara and Janco position themselves in relation to their national identity, arguing for a complex relationship between origin and artistic production that goes beyond simple identity. In short, the discussion is built around the argument that becoming offers a new platform to explore the linkage between Tzara’s and Janco’s inherited Jewishness, their lack of citizenship and the nation-state amidst which they were living. In conclusion, this research seeks to clear the way for a renewed consideration of the symbolic substance of Tzara’s and Janco’s Jewish experience and the role it played in defining their national identity

Mapping affinities: visualizing academic practice through collaboration

Academic affinities are one of the most fundamental hidden dynamics that drive scientific development. Some affinities are actual, and consequently can be measured through classical academic metrics such as co-authoring. Other affinities are potential, and therefore do not have visible traces in information systems; for instance, some peers may share scientific interests without actually knowing it. This thesis illustrates the development of a map of affinities for scientific collectives, which is intended to be relevant to three audiences: the management, the scholars themselves, and the external public. Our case study involves the School of Architecture, Civil and Environmental Engineering of EPFL, which consists of three institutes, seventy laboratories, and around one thousand employees. The actual affinities are modeled using the data available from the academic systems reporting publications, teaching, and advising, whereas the potential affinities are addressed through text mining of the documents registered in the information system. The major challenge for designing such a map is to represent the multi-dimensionality and multi-scale nature of the information. The affinities are not limited to the computation of heterogeneous sources of information, they also apply at different scales. Therefore, the map shows local affinities inside a given laboratory, as well as global affinities among laboratories. The thesis presents a graphical grammar to represent affinities. This graphical system is actualized in several embodiments, among which a large-scale carpet of 250 square meters and an interactive online system in which the map can be parameterized. In both cases, we discuss how the actualization influences the representation of data, in particular the way key questions could be appropriately addressed considering the three target audiences: the insights gained by the management and the relative decisions, the understanding of the researchersâ own positioning in the academic collective that might reveal opportunities for new synergies, and eventually the interpretation of the structure from an external standpoint that suggesting the relevance of the tool for communication