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We address the problem of shaping the radiant intensity distribution of a highly nonparaxial coherent field by means of a diffractive element located in the plane of the beam waist. To be capable of wide-angle energy redistribution the element must necessarily contain wavelength-scale transverse features, and consequently it must be designed on the basis of rigorous diffraction theory. We consider, in particular, wide-angle Gaussian to flat-top beam shaping in one dimension. Scalar designs are provided and their validity is evaluated by rigorous diffraction theory, which is also used for optimization deep inside the nonparaxial domain, where the scalar designs fail. Experimental verification is provided by means of electron-beam lithography. 相似文献
43.
Roberto Boselli Mirko Cesarini Stefania Marrara Fabio Mercorio Mario Mezzanzanica Gabriella Pasi Marco Viviani 《Journal of Intelligent Information Systems》2018,51(3):477-502
In the last decades, an increasing number of employers and job seekers have been relying on Web resources to get in touch and to find a job. If appropriately retrieved and analyzed, the huge number of job vacancies available today on on-line job portals can provide detailed and valuable information about the Web Labor Market dynamics and trends. In particular, this information can be useful to all actors, public and private, who play a role in the European Labor Market. This paper presents WoLMIS, a system aimed at collecting and automatically classifying multilingual Web job vacancies with respect to a standard taxonomy of occupations. The proposed system has been developed for the Cedefop European agency, which supports the development of European Vocational Education and Training (VET) policies and contributes to their implementation. In particular, WoLMIS allows analysts and Labor Market specialists to make sense of Labor Market dynamics and trends of several countries in Europe, by overcoming linguistic boundaries across national borders. A detailed experimental evaluation analysis is also provided for a set of about 2 million job vacancies, collected from a set of UK and Irish Web job sites from June to September 2015. 相似文献
44.
The Social Web is characterized by a massive diffusion of unfiltered content, directly generated by users via the spread of different social media platforms. In this context, a challenging issue is to assess the veracity of the information generated within the sites of online reviews. To address this issue, a common practice in the literature is to select and analyze some veracity features associated with users and their reviews, by mostly applying machine learning techniques, to provide a classification in genuine and deceptive reviews. In this paper, we do not focus on the feature selection and user behavior analysis issues, but we concentrate on the aggregation process with respect to each single veracity feature. In most of the approaches based on machine learning techniques, the contribution of each feature in the classification process is not measurable by the user. For this reason, we propose a multicriteria decision making approach based both on the assessment of multiple criteria and the use of aggregation operators with the aim of obtaining a veracity score associated with each review. Based on this score, it is possible to detect fake reviews. The proposed model is evaluated on a Yelp data set by applying different aggregation schemes, and it is compared with well‐known supervised machine learning techniques. 相似文献
45.
46.
Pasi Ylä-Oijala Sami P. Kiminki Seppo Järvenpää 《Engineering Analysis with Boundary Elements》2013,37(1):68-73
Various combined source integral equation (CSIE) formulations are developed for the analysis of electromagnetic scattering by three-dimensional arbitrarily shaped homogeneous penetrable objects. The considered CSIE formulations include the classical “electric” CSIE proposed by Mautz and Harrington in 1979, and its dual “magnetic” CSIE as well as mixed “electric–magnetic” and “magnetic–electric” CSIE formulations. Novel discretization schemes by utilizing the primary (Rao–Wilton–Glisson, RWG) and the dual (Buffa–Christiansen, BC) functions are applied to convert the integral equations into matrix equations. These schemes avoid the numerical problems that would appear if the CSIE formulations were discretized with the conventional Galerkin method using the RWG functions only. 相似文献
47.
Ville Tähtinen Alejandra Verhassel Dr. Johanna Tuomela Prof. Pasi Virta 《Chembiochem : a European journal of chemical biology》2019,20(24):3041-3051
γ-Modified (i.e., (S)-aminomethyl, (S)-acetamidomethyl, (R)-4-(hydroxymethyl)triazol-1-ylmethyl, and (S)-guanidinylmethyl) triplex-forming peptide nucleic acids (TFPNAs) were synthesized and the effect of the backbone modifications on the binding to a miR-215 model was studied. Among the modifications, an appropriate pattern of three γ-(S)-guanidinylmethyl modifications increased the affinity and Hoogsteen-face selectivity for the miR-215 model without ternary (PNA)2/RNA complex formation. Moreover, the γ-(S)-guanidinylmethyl groups were observed to facilitate internalization of the TFPNAs into living PC-3 prostate cancer cells. 相似文献
48.
Jesper Lundbom Marjukka Kolehmainen Leena Pulkkinen Pasi Soininen Mika Tiainen Ursula Schwab Matti Uusitupa Markku Tammi 《European Journal of Lipid Science and Technology》2010,112(12):1308-1314
The aim of this study was to evaluate use of infrared spectroscopy for measuring adipose tissue triacylglycerols (TAGs) with analysis by multivariate curve resolution (MCR). The mid‐infrared spectrum was measured with an attenuated total reflection accessory from a lipid droplet pressed from adipose tissue. The obtained spectra were characteristic of pure TAG spectra and water and protein contamination could be easily identified from specific spectral regions. MCR analysis of the olefinic (?C? H) stretch (3006 cm?1), resolved the different contributions of monounsaturated (MUFA) and polyunsaturated (PUFA) double bonds. Similar MCR analysis of the trans (HC?CH? ) region (966 cm?1), resolved the differing contributions of isolated trans isomers (transFA) and CLA. The PUFA double bond content of 16 subjects was negatively correlated with concentrations of serum total cholesterol R = ?0.498 (p = 0.050) and triacylglycerols R = ?0.609, (p = 0.016). The transFA content exhibited a negative, although non‐significant, correlation to high‐density lipoprotein (HDL)‐cholesterol (R = ?0.483, p = 0.068). The present study shows that MCR analysis of adipose tissue TAG infrared spectra can be used to estimate differences in the fatty acid (FA) profiles in population studies. Infrared spectroscopy in combination with MCR provides a robust method for assessing a FA profile of human adipose tissue. Practical applications: This study has highlighted the use of MCR to enhance the information obtained from infrared spectra. This new approach provides a robust method for assessing a FA profile of human adipose tissue lipids. 相似文献
49.
Vallius T Tervo J Vahimaa P Turunen J 《Journal of the Optical Society of America. A, Optics, image science, and vision》2006,23(4):906-911
An electromagnetic method based on rigorous diffraction theory of gratings is applied to the analysis of fields in semiconductor laser cavities. The method is based on the Fourier modal method; it is fully rigorous for infinitely periodic resonators and highly accurate for single resonators when absorbing boundary conditions are applied. Fundamental-mode intracavity and near-field distributions are evaluated for some selected geometries, and resonance frequencies are predicted. 相似文献
50.
Laakkonen P Siitonen S Kuittinen M 《Journal of the Optical Society of America. A, Optics, image science, and vision》2006,23(12):3156-3161
A double-groove, two-depth dielectric grating structure for high-efficiency light coupling into a light guide is introduced. We show computationally that the optimized gratings can couple a monochromatic TE- or TM-polarized light beam with nearly 100% efficiency. For an unpolarized light beam 90% efficiency can be reached. In all cases the highest achieved coupling efficiencies require that the refractive index of the grating material be greater than 1.7. The illumination and fabrication tolerances of the couplers are also analyzed. 相似文献