Untangling Gaussian Mixtures

Tangles were originally introduced as a concept to formalize regions of high connectivity in graphs. In recent years, they have also been discovered as a link between structural graph theory and data science: when interpreting similarity in data sets as connectivity between points, finding clusters in the data essentially amounts to finding tangles in the underlying graphs. This paper further explores the potential of tangles in data sets as a means for a formal study of clusters. Real-world data often follow a normal distribution. Accounting for this, we develop a quantitative theory of tangles in data sets drawn from Gaussian mixtures. To this end, we equip the data with a graph structure that models similarity between the points and allows us to apply tangle theory to the data. We provide explicit conditions under which tangles associated with the marginal Gaussian distributions exist asymptotically almost surely. This can be considered as a sufficient formal criterion for the separabability of clusters in the data

Recursos, capacidades y competencias para la eco-innovación empresarial

Pablo del Río González, codirector externo del CSICTesis Premio Extraordinario de Doctorado de la UAH en el año académico 2016-2017El actual sistema económico no es sostenible por ser lineal y abierto, lo que lleva al deterioro del medio ambiente. La economía circular puede ser sostenible desde la perspectiva económica, ecológica y social (el triple resultado). La transición hacia esta sostenibilidad se puede alcanzar mediante eco-innovaciones.A pesar de las abundantes contribuciones en este campo, la literatura no ha logrado aún alcanzar un consenso sobre un concepto universal de la eco-innovación. Asimismo, existe relativamente poco conocimiento acerca de sus antecedentes empresariales. Todavía no se conocen los determinantes y barreras precisas para la eco-innovación. Sin embargo, este conocimiento es necesario para lograr dicha transformación hacia la sostenibilidad. También es relevante para las empresas y las políticas económicas públicas, ya que la eco-innovación es una fuente tanto de sostenibilidad como de competitividad. Esta Tesis Doctoral recoge datos primarios mediante una encuesta propia a pequeñas y medianas empresas (PYMES) españolas del sector industrial. Emplea análisis factoriales exploratorios, análisis de conglomerados y análisis de regresión multinomial logística (logit).Los resultados empíricos revelan las características fundamentales de la eco-innovación, así como los recursos, capacidades y competencias existentes en las empresas eco-innovadoras. Además, permiten plantear una nueva taxonomía de cinco principales tipos de eco-innovación realizados por las empresas estudiadas. Asimismo, se muestran los determinantes y barreras empresariales precisos que influyen en cada una de esas tipologías de eco-innovación. Las implicaciones de esta investigación comprenden recomendaciones específicas para el fomento de los antecedentes empresariales para la eco-innovación, tanto por la propia iniciativa de las empresas como por las políticas económicas públicas

Communication Between Process and Structure: Modelling and Simulating Message Reference Networks with COM/TE

Focusing on observable message signs and referencing structures, communication processes can be described and analysed as message reference networks which are characterized by dynamic pattern evolution. Computational simulation provides a way of obtaining insights into the factors driving such processes. Our paper describes a theoretical framework for communication-oriented modelling — the COM approach — that is centred around the notion of social visibility as a reputation mechanism. The approach contrasts with agent-based social networks on the one hand, and with bibliometric document networks on the other. In introducing our simulation environment COM/TE, typical properties of message reference networks are discussed in terms of a case study which deals with the impact of different media and styles of communication on emergent patterns of social visibility.Communication, Communication-Oriented Modelling, Message Sign, Dynamic Networks, Bottom-up Approach, Temporality, Social Visibility, Reputation, Socionics

Building a taxonomy of eco-innovation types in firms: A quantitative perspective

Eco-innovations, or innovations that reduce the environmental impacts of production and consumption activities, are considered crucial for sustainability transitions and a key element of a Circular Economy. Although previous contributions have acknowledged the existence of different types of eco-innovations (e.g., product vs. service or incremental vs. radical), a precise conceptualization of eco-innovation types, which takes into account its multifaceted character, is missing. Yet such a conceptualization is crucial in order to understand how eco-innovations contribute to a sustainable transition, how policy makers can promote different eco-innovation types, and how business practitioners can develop eco-innovations. This article covers this gap in the literature. Its aim is twofold: 1) to develop a quantitative method to categorise different eco-innovation types in a particular setting, taking into account their distinct features and dimensions; 2) to apply this method in a given sector and country, building a taxonomy of eco-innovation types. It draws on a survey of 197 Spanish industrial small and medium size enterprises (SMEs) which developed or adopted an eco-innovation between 2012 and 2013. The statistical analyses reveal the existence of a taxonomy of five eco-innovation types: systemic, externally driven, continuous improvement, radical (technology-push initiated) and eco-efficient. They differ in their techno-economic configurations, contribution to environmental sustainability and corporate goals and required changes in the firms. Specific policy and managerial implications are deducted

Drivers and barriers of eco-innovation types for sustainable transitions: A quantitative perspective

Firms are influenced by internal factors (resources and capabilities) and external factors (e.g., regulation) when taking the decision to eco-innovate. However, the analysis of the internal factors has received much less attention than the external ones. This paper aims to fill this gap in the literature by analyzing the role of resources, competences, and dynamic capabilities (RCCs) as determinants (drivers and barriers) of different eco-innovation (EI) types. Those EI types contribute differently to the sustainable transition of the economy and society, that is, towards the circular economy. The statistical analyses reveal that RCCs are quite relevant as determinants of EIs, and that different RCCs are more or less relevant for different EI types. In particular, the determinants of systemic and radical EIs substantially differ from those for continuous improvements. Our results suggest that physical RCCs, involvement in green supply chains, an EI-friendly corporate culture, technology-push and market-pull, and internal financing resources represent drivers to these EIs, whereas cooperation, organizational learning, an ISO (International Organization for Standardization) ecological certification, and technological path dependency are barriers. The results may guide firms to pursue competitive and sustainable advantage by innovating through certain EI types corresponding to available and dedicated RCCs. They may also be useful to policy makers who are willing to promote specific EI types

On the Size of Finite Rational Matrix Semigroups

Let $n$ be a positive integer and $\mathcal M$ a set of rational $n \times n$-matrices such that $\mathcal M$ generates a finite multiplicative semigroup. We show that any matrix in the semigroup is a product of matrices in $\mathcal M$ whose length is at most $2^{n (2 n + 3)} g(n)^{n+1} \in 2^{O(n^2 \log n)}$, where $g(n)$ is the maximum order of finite groups over rational $n \times n$-matrices. This result implies algorithms with an elementary running time for deciding finiteness of weighted automata over the rationals and for deciding reachability in affine integer vector addition systems with states with the finite monoid property

A Hybrid Approach to Describe the Elastic-Plastic Deformation Behavior of 2D Cellular Solids Including Damage Effects

The constitutive description of the inelastic deformation behavior of porous media is a challenging task. The complex hardening behavior (simultaneous isotropic, kinematic and distortional hardening) and anisotropic yielding depend strongly on the micro-structure of the porous medium and the inelastic behavior of its bulk material.  In previous work, the authors presented a homogenized material model for an elastic-plastic material at the microscopic scale based on an adapted yield function to describe the elastic-plastic deformation behavior, including damage, of open-cell structures. In this approach, the shape of the yield function is not specified completely a priori. The proper shape is rather found by regression with results of cell model simulations using neural networks. The aim of this contribution is to demonstrate that this hybrid approach shows good agreement with direct simulations. The necessary size of the neural network, the number of training data and the computational efficiency are also discussed. It can be concluded that this model can be used to analyze the deformation behavior of porous structures while considering the coupling of plastic deformations and damage of the bulk material

Das Versprechen der Soziologie

In den Debatten um das Verhältnis von Soziologie und Kritik sowie um Public Sociology wird die Disziplin stets auf die eine oder andere Weise mit gesellschaftskritischer Theorie und Praxis verknüpft. Ausgehend von der Überlegung, dass dieses besondere Verhältnis zur Kritik ein Versprechen auf kritisch-emanzipatorische Inhalte und Praxis als Kernelement der Soziologie darstellt, wird hier in einer explorativen Studie nach der Relevanz dieses Versprechens für die Studienmotivation sowie das Rollen- und Disziplinverständnis von Studierenden der Soziologie in Deutschland gefragt, deren Perspektive in den genannten Debatten bislang unterrepräsentiert ist. Mit Hilfe eines Onlinefragebogens wurden hierfür 1068 Studierende der Soziologie und Sozialwissenschaften befragt. Es zeigt sich, dass die Zustimmung zu einem kritisch-emanzipatorischen Verständnis der Disziplin und der eigenen Rolle als Soziolog*in durchgehend hoch ist, diese Zustimmung jedoch nicht in unmittelbaren Zusammenhang mit zentralen Sozialstrukturvariablen gebracht werden kann. Studienstandort und Position im Studienverlauf hingegen erweisen sich als deutliche Einflussgrößen. Die Ergebnisse zeigen die Bedeutung und das strukturierende Potential der hier verhandelten Fragestellung für eine Analyse des soziologischen Felds in Deutschland und den Bedarf an weiterer selbstreflexiver Forschung. In the debates about public sociology and about the relationship between sociology and criticism, the discipline is always linked in one way or another with social critique. Based on the premise that this special relationship to criticism is a promise for critical-emancipatory theory and praxis to be a core element of sociology, we conducted an exploratory study on the relevance of this promise for the study motivation as well as the individual role and the general understanding of the discipline of sociology students in Germany, whose perspective is so far underrepresented in the debates mentioned. An online questionnaire asked 1068 students of sociology and social sciences. It is shown that the consent to a criticalemancipatory understanding of the discipline and of the student’s own role as a sociologist is thoroughly endorsed, but this consent cannot be brought into direct connection with central social structure variables. However, the place of study and the position in the course of studies prove to be significant factors. The results illustrate the importance and the structuring potential of the question discussed here for an analysis of the sociological field in Germany and show the need for further self-reflective research