Combinatorial Variations on Cantor's Diagonal

We discuss counting problems linked to finite versions of Cantor's diagonal of infinite tableaux. We extend previous results of [2] by refining an equivalence relation that reduces significantly the exhaustive generation. New enumerative results follow and allow to look at the sub-class of the so- called bi-Cantorian tableaux. We conclude with a correspondence between Cantorian-type tableaux and coloring of hypergraphs having a square number of vertices

Représentation spatiale pour une gestion patrimoniale des ressources en eau: Application au bassin de la Vègre

National audienceThe sustainable exploitation of the water resources imply an integrated management at the catchment scale. The objective is to overcome the conflicts between the different parties involved in the negociation, inherent in competition with the incompatibility between certain uses of water. As a preliminary, the local decision makers must be able to acquire a common knowledge of the environment and uses of water for better appreciating the stakes. This knowledge is indeed essential so that they overcome a vision often too sectorial. The initial inventory implies a spatial representation of information highlighting their diversity. It is also necessary to synthesize the data according to the concerns of the decision makers in order to improve their legibility and thus the local thought. This poses in particular the problem of the adequacy between the data available and the scale of decision.The Geographical Information Systems are means adapted to work out supports with the discussion between the participants in the decision-making process (associations of users, elected officials, administrations). They can improve the communication and make more rational the decision-making process by highlighting objective data. The study of the catchment area of Vègre (Sarthe, France) illustrates the contributions of such a step.L'exploitation et à la préservation des ressources en eau impliquent une gestion intégrée à l'échelle de bassins versants. L'objectif est de surmonter les conflits entre acteurs, inhérents à la concurrence voire à l'incompatibilité entre certains usages de l'eau. Au préalable, les acteurs locaux doivent pouvoir acquérir une connaissance globale des milieux et des usages de l'eau pour mieux apprécier les enjeux. Cette connaissance est en effet indispensable pour qu'ils dépassent une vision souvent trop sectorielle.L'état des lieux implique une représentation spatiale des informations mettant en évidence leur diversité. Il est également nécessaire de synthétiser les données en fonction des préoccupations des acteurs locaux afin d'améliorer leur lisibilité et ainsi la réflexion locale. Ceci pose notamment le problème de l'adéquation entre les données disponibles et l'échelle de décision Les Systèmes d'Information Géographique sont des moyens adaptés pour élaborer des supports à la discussion entre les intervenants dans le processus de décision (associations d'usagers, élus, administrations). Ils peuvent effectivement améliorer la communication et rendre plus rationnel le processus de décision en mettant en évidence des données objectives.L'étude du bassin versant de la Vègre (Sarthe) illustre les apports d'une telle démarche

A guided analytics tool for feature selection in steel manufacturing with an application to blast furnace top gas efficiency

In knowledge intensive industries such as steel manufacturing, application of data analytics to optimise process performance, requires effective knowledge transfer between domain experts and data scientists. This is often an inefficient path to follow, requiring much iteration whilst being suboptimal with regard to organisational knowledge capture for the long term. With the ‘initial Guided Analytics for parameter Testing and controlband Extraction (iGATE)’ tool we created a feature selection framework that finds influential process parameters and their optimal control bands and which can easily be made available to process operators in the form of guided analytics tool, while allowing them to modify the analysis according to their expertise. The method is embedded in a work flow whereby the extracted parameters and control bands are verified by the domain expert and a report of the analysis is automatically generated. The approach allows us to combine the power of suitable statistical analysis with process-expertise, whilst dramatically reducing the time needed for conducting the feature selection. We regard this application as a stepping stone to gain user confidence in advance of introduction of more autonomous analytics approaches. We present the statistical foundations of iGATE and illustrate its effectiveness in the form of a case study of Tata Steel blast furnace data. We have made the iGATE core functionality freely available in the igate package for the R programming language

CROWDWORK PLATFORMS: JUXTAPOSING CENTRALIZED AND DECENTRALIZED GOVERNANCE

Crowdwork is a novel form of digitally mediated work arrangement that is managed and organized through online labor platforms. This paper focuses on the governance of platforms that facilitate creative work—that is, complex work tasks that require high-level skill and creative workers. Crowdwork platform governance faces numerous challenges as a result of technology mediation, scalable and distributed workers, and temporary work arrangements. Creative crowdwork platforms, such as Topcoder, typically require additional governance structures to manage complex tasks. However, we know relatively little about creative crowdwork platform governance, as most existing studies focus on routine work platforms, such as Amazon Mechanical Turk. Accordingly, this paper explores how incumbent and insurgent creative crowdwork platforms are governed under centralized and decentralized modes. We conducted a comparative case study based on the analysis of two different cases: Topcoder, a successful commercial platform with a largely centralized governance structure, and CanYa, an emerging innovative platform based on blockchain technology with more decentralized governance. We identified and classified different governance elements related to work control and work coordination. In addition, we explored the characteristics of creative crowdwork platform governance with different degrees of centralization. Keywords: Crowdwork Governance, Creative Crowdwork, Centralized Platforms, Decentralized Platforms, Blockchain, Tokenomics

Selective cleavage of 28S rRNA variable regions V3 and V13 in myeloid leukemia cell apoptosis

AbstractVigorous apoptosis is induced 3–4 hours after activation of cAMP-dependent protein kinase I in the rat myeloid leukemia cell line IPC-81 [J. Cell. Physiol. 146 (1991) 73-80]. We will report a novel feature of apoptosis in these cells: a selective and temporarily ordered cleavage within the two largest 28S ribosomal RNA variable regions (V3 and V13). The cleavage of 28S rRNA coincided with internucleosomal DNA fragmentation and cessation of cellular protein synthesis. The implication of 28S variable regions as targets in apoptosis is a clue to the function of these so far apparently superfluous parts of eukaryotic ribosomes

Mode excitation by turbulent convection in rotating stars. I. Effect of uniform rotation

We focus on the influence of the Coriolis acceleration on the stochastic excitation of oscillation modes in convective regions of rotating stars. Our aim is to estimate the asymmetry between excitation rates of prograde and retrograde modes. We extend the formalism derived for obtaining stellar $p$- and $g$-mode amplitudes (Samadi & Goupil 2001, Belkacem et al. 2008) to include the effect of the Coriolis acceleration. We then study the special case of uniform rotation for slowly rotating stars by performing a perturbative analysis. This allows us to consider the cases of the Sun and the CoRoT target HD 49933. We find that, in the subsonic regime, the influence of rotation as a direct contribution to mode driving is negligible in front of the Reynolds stress contribution. In slow rotators, the indirect effect of the modification of the eigenfunctions on mode excitation is investigated by performing a perturbative analysis of the excitation rates. It turns out that the excitation of solar $p$ modes is affected by rotation with excitation rates asymmetries between prograde and retrograde modes of the order of several percents. Solar low-order $g$ modes are also affected by uniform rotation and their excitation rates asymmetries are found to reach up to 10 %. The CoRoT target HD 49933 is rotating faster than the Sun ($\Omega / \Omega_\odot \approx 8$) and we show that the resulting excitation rates asymmetry is about 10 % for the excitation rates of $p$ modes. We have then demonstrated that $p$ and $g$ mode excitation rates are modified by uniform rotation through the Coriolis acceleration. Study of the effect of differential rotation is dedicated to a forthcoming paper.Comment: 9 pages, 4 figures, accepted in A&

Reclaiming the European City and Lobbying for Privilege: Business Improvement Districts in Germany

Business Improvement Districts (BIDs) are an increasing global phenomenon. In diverse places, they are established and sought of as helpful means to improve urban places. BIDs are frequently seen as a showcase for new forms of globalizing urban policies. This paper contrasts and broadens the frequent examples from the United States and the United Kingdom with experiences from Germany. We argue that this presents not just another example of BIDs as a mode of global neoliberal urban governance in yet another country. Instead, our case study highlights the elasticity and resilience of said concept and the impact of local trajectories on the mobilization of modes of urban governance. Compared with other places, BIDs in Germany remain relatively weak in terms of financial power. Nonetheless, the case of Hamburg shows how they are made suitable for discourses and practices of a neoliberalized “European City.

Inductive Freeness of Ziegler's Canonical Multiderivations for Reflection Arrangements

Let $A$ be a free hyperplane arrangement. In 1989, Ziegler showed that the restriction $A''$ of $A$ to any hyperplane endowed with the natural multiplicity is then a free multiarrangement. We initiate a study of the stronger freeness property of inductive freeness for these canonical free multiarrangements and investigate them for the underlying class of reflection arrangements. More precisely, let $A = A(W)$ be the reflection arrangement of a complex reflection group $W$. By work of Terao, each such reflection arrangement is free. Thus so is Ziegler's canonical multiplicity on the restriction $A''$ of $A$ to a hyperplane. We show that the latter is inductively free as a multiarrangement if and only if $A''$ itself is inductively free.Comment: 23 pages; v2 minor changes; final version, to appear in J. Algebr