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Intro -- Foreword -- Preface -- Introduction -- Contents -- Contributors -- Knowledge Communities and Socio-Cognitive Taxonomies -- 1 Introduction -- 2 Communities in Interaction Networks -- 2.1 Explicit vs. Procedural Methods -- 2.2 Structural Properties of Groups -- 3 Reuniting Structure and Content -- 3.1 Affiliation Networks, Social Circles, and FCA -- 3.2 Formal Concepts as Epistemic Communities -- 4 Applications -- 4.1 Datasets -- 4.2 Socio-Cognitive Taxonomies -- 5 Concluding Remarks -- References -- Individuality in Social Networks -- 1 Introduction -- 2 Related Work -- 3 Social Networks as Formal Contexts -- 4 Individuality of Social Networks -- 5 Experimental Results -- 5.1 Data and Modeling -- 5.1.1 Club Membership Network (CM) konect:2016:brunsonclub-membership -- 5.1.2 Facebook-Like Forum Network (FB) opsahl2009clustering -- 5.1.3 Lange Nacht der Musik (LNM) Schaller2014a -- 5.1.4 Norwegian Board Members (NB) norwegianBoarddataset -- 5.1.5 Southern Women (SW) wasserman1994 -- 5.2 Small World Network Properties -- 5.2.1 Average Shortest Path -- 5.2.2 Average Local Clustering Coefficient -- 5.2.3 Summary -- 5.3 Group Individuality -- 5.4 Individuality Distribution -- 5.5 Average Millieu Size -- 5.6 Discussion and Interpretation -- 6 Conclusions and Outlook -- References -- Descriptive Community Detection -- 1 Introduction -- 2 Subgroup Discovery -- 2.1 Patterns and Subgroups -- 2.2 Interestingness of a Pattern -- 2.3 Community Detection -- 2.3.1 Basics of Community Detection -- 2.3.2 Detecting Overlapping Communities -- 2.4 Exceptional Model Mining -- 3 Community Detection and Description -- 4 Community Detection Using Exceptional Model Mining -- 4.1 COMODO: Description-Oriented Community Detection -- 4.1.1 Algorithmic Overview -- 4.1.2 Illustrative Evaluation Results

The book studies the existing and potential connections between Social Network Analysis (SNA) and Formal Concept Analysis (FCA) by showing how standard SNA techniques, usually based on graph theory, can be supplemented by FCA methods, which rely on lattice theory. The book presents contributions to the following areas: acquisition of terminological knowledge from social networks, knowledge communities, individuality computation, other types of FCA-based analysis of bipartite graphs (two-mode networks), multimodal clustering, community detection and description in one-mode and multi-mode networks, adaptation of the dual-projection approach to weighted bipartite graphs, extensions to the Kleinberg's HITS algorithm as well as attributed graph analysis.

The following article appeared in Rodríguez-Ulibarri, P., Beruete, M., & Kuznetsov, S. (2016). Wide angle terahertz sensing with a cross-dipole frequency selective surface. Applied Physics Letters, 108(11), doi:10.1063/1.4944326 and may be found at http://dx.doi.org/doi:10.1063/1.4944326. ; In this work, a terahertz sensor based on a cross dipole frequency selective surface is analyzed and experimentally tested. The sensing structure is optimized for operation at the fundamental band- stop resonance near 0.7THz and characterized under normal and oblique incidence. The sensing performance as a function of the incidence angle and the wave polarization is evaluated with good agreement between simulations and measurements. It is shown that a figure of merit for the pro- posed sensor can be enhanced from 0.2 up to 0.6 due to switching from normal to oblique excita- tion, which yields the maximum performance for TM polarization at the incidence angle of 70º. The presented results demonstrate a wide angle operation regime in THz sensing that opens up an alternative approach in improving capabilities of sensing devices. ; This work was sponsored by the Spanish Government under Contract Nos. TEC2011-28664-C02-01 and TEC2014-51902-C2-2-R. P.R.-U. was sponsored by Public University of Navarra via a predoctoral scholarship. M.B. was sponsored by the Spanish Government via RYC-2011- 08221

Scientists and laymen alike have always been fascinated by the ability of lenses and mirrors to control light. Now, with the advent of metamaterials and their two-dimensional counterpart metasurfaces, such components can be miniaturized and designed with additional functionalities, holding promise for system integration. To demonstrate this potential, here ultrathin reflection metasurfaces (also called metamirrors) designed for focusing terahertz radiation into a single spot and four spaced spots are proposed and experimentally investigated at the frequency of 0.35 THz. Each metasurface is designed using a computer-generated spatial distribution of the reflection phase. The phase variation within 360 deg is achieved via a topological morphing of the metasurface pattern from metallic patches to U-shaped and split-ring resonator elements, whose spectral response is derived from full-wave electromagnetic simulations. The proposed approach demonstrates a high-performance solution for creating low-cost and lightweight beam-shaping and beam-focusing devices for the terahertz band. ; This work was supported by the Ministry of Education and Science of the Russian Federation under the State Assignment Contract #3002 (implementation of the Gerchberg-Saxton iterative algorithm and experimental testing), the Russian Science Foundation under the Project 14-12-01037 (full-wave electromagnetic simulations), and the Spanish Government under contracts Consolider "Engineering Metamaterials" CSD2008-00066, and TEC2011-28664-C01. M. Beruete acknowledges funding by the Spanish Government under the research contract program Ramón y Cajal RYC-2011-08221. M. N.-C. was supported by Imperial College London through a Junior Research Fellowship.

In this letter we present an in-depth circuit analysis of anomalous extraordinary transmission ET through subwavelength slit and hole arrrays loaded by a dielectric slab. We show the key role played by the thickness of the dielectric slab in order to enhance the transmission for TE-polarized waves incident electric field parallel to the slits or to the short in-plane period in hole arrays arranged in rectangular lattice within the cut-off regime of the apertures and to suppress Wood's anomaly. Analytical and numerical results together with experimental data are presented, showing good agreement among them. This work provides physical insight of the underlying mechanism governing anomalous ET and offers further independent control over orthogonal polarized waves impinging into subwavelength aperture arrays. ; This work has been supported by the Spanish Government under contracts Consolider "Engineering Metamaterials" Grant Nos. CSD2008-00066 and TEC2008-06871-C02-01.

This is the peer reviewed version of the following article: M. Navarro-Cía, V. Pacheco-Peña, S. A. Kuznetsov, M. Beruete: Extraordinary THz Transmission with a Small Beam Spot: The Leaky Wave Mechanism. Advanced Optical Materials 2018, 1701312, which has been published in final form at https://doi.org/10.1002/adom.201701312. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. ; The discovery of extraordinary optical transmission (EOT) through patterned metallic foils in the late 1990s was decisive for the development of plasmonics and cleared the path to employ small apertures for a variety of interesting applications all along the electromagnetic spectrum. However, a typical drawback often found in practical EOT structures is the large size needed to obtain high transmittance peaks. Consequently, practical EOT arrays are usually illuminated using an expanded (mimicking a plane wave) beam. Here, it is shown with numerical and experimental results in the THz range that high transmittance peaks can be obtained even with a reduced illumination spot exciting a small number of holes, provided that the structure has a sufficient number of lateral holes out of the illumination spot. These results shed more light on the prominent role of leaky waves in the underlying physics of EOT and have a direct impact on potential applications. ; This work was partially supported by the Spanish Ministerio de Economía y Competitividad with European Union Fondo Europeo de Desarrollo Regional (FEDER) funds [TEC2014-51902-C2-2-R]. M.N.-C. acknowledges support from University of Birmingham [Birmingham Fellowship]. V.P.-P. was sponsored by Spanish Ministerio de Educación, Cultura y Deporte [formación de profesorado universitario (FPU) AP-2012-3796]. S.A.K. acknowledges support from the Novosibirsk State University (NSU) program 5-100 established by the Russian Ministry of Education and Science.

Subwavelength hole array (HA) metasurfaces support the so-called extraordinary optical transmission (EOT) resonance that has already been exploited for sensing. In this work, we demonstrate the superior performance of a different resonant regime of HA metasurfaces called anomalous EOT, by doing a thorough numerical and experimental study of its ability in thin-film label-free sensing applications in the terahertz (THz) band. A comprehensive analysis using both the regular and anomalous EOT resonances is done by depositing thin layers of dielectric analyte slabs of different thicknesses on the structures in different scenarios. We carry out a detailed comparison and demonstrate that the best sensing performance is achieved when the structure operates in the anomalous EOT resonance and the analyte is deposited on the non-patterned side of the metasurface, improving by a factor between 2 and 3 the results of the EOT resonance in any of the considered scenarios. This can be explained by the comparatively narrower linewidth of the anomalous EOT resonance. The results presented expand the reach of subwavelength HAs for sensing applications by considering the anomalous EOT regime that is usually overlooked in the literature. ; This research was funded by the Spanish Ministerio de Economía y Competitividad with European Union Fondo Europeo de Desarrollo Regional (FEDER) funds, grant number TEC2014-51902-C2-2-R. The work was partially supported by the Russian Foundation for Basic Research (Project No. 17-32-80039, experimental study; Project No. 18-29-20066, technological implementation).

In this paper Anomalous Extraordinary Transmission (ET) is reported for s-polarization of low loss doubly periodic subwavelength hole arrays patterned on polypropylene (PP) substrates by conventional contact photolithography at the so-called THz-gap (1-10 THz). The unexpected enhanced transmittance for s-polarization (i.e. without spoof plasmons) was previously numerically demonstrated in subwavelength slits arrays. However, subsequently no experimental work has been devoted to this unexpected Extraordinary Transmission neither in subwavelength slits nor in subwavelength holes. Here, numerical study and experimental results of the Anomalous ET and the symmetric and antisymmetric transmittance modes associated with the already well-known p-polarization ET are shown alongside a systematically analysis of the frequency peaks as a function of hole size for both incident polarizations. ; This work was supported by Spanish Government and E.U. Feder under contracts Consolider "Engineering Metamaterials" CSD2008-00066 and TEC2008-06871-C02-01.