1,721,074 research outputs found
WHY SHOULD WE CARE ABOUT INNOVATION? WHAT ARE THE KEY ARGUMENTS TO SAY THAT "NEW TECHNOLOGY" NECESSARILY CAUSES WEALTH AND BENEFIT FOR SOCIETY? WHAT ARE THE LIMITS OF THESE ARGUMENTS?
Get PDFThis paper discussed the importance of innovation generally and also taking into account the ASP project "Integrated Technologies for the Sustainable Management of Underwater Cultural Heritage (TETI)" as a case study. The paper elaborated the feathers of innovation that can affect the innovative process and the necessity to develop innovative solutions for the success and development of the market. The paper also discussed the key arguments like "new technology" necessarily causes wealth and benefit for society, the factors that can affect the new technology and the limits of these arguments
Models: what are they and why are they useful
Get PDFThis paper discussed what the models are and why they are useful. The paper elaborated the characteristics, costs and different kinds of models. The art of modeling is also highlighted with respect to descriptive and decisional problems. The paper also discussed the mathematical modeling of Love dynamics, and analyzed the Robust & Fragile couples as well as High & Low quality relationships
Measurement and Uncertainty Assessment using Vector Network Analyzer (VNA) up to Terahertz Frequency Band
No full textIn RF and microwave engineering, the vector network analyzers (VNAs) are commonly used for network analysis with great accuracy and precision. VNAs are complex and versatile instruments employed to characterize active and passive networks. The network characterization is defined in terms of scattering parameters (S-parameters). The S-parameters are ratios of wave quantities which provide information about reflection and transmission characteristics of the device under test (DUT). The VNA measurements are associated with different sources of errors; mainly classified as systematic, random and drift errors. During a VNA calibration procedure, the systematic errors are characterized and most of them are mathematically removed afterwards. The other sources of errors can possibly be minimized, however, they affect the S-parameter measurements and become different sources of uncertainty associated with the measurements. Therefore, the uncertainty analysis is also an integral part while doing measurements with VNAs. The aim of this thesis is to perform VNA measurements and uncertainty assessments in both coaxial and waveguide test-set environments. The frequency of interest ranges from few MHz up to Terahertz frequency band. The uncertainty analysis is performed both numerically and analytically. The uncertainty sources considered are the definitions of the calibration standards, VNA noise, repeatability and drift. The different uncertainty sources are linearly propagated to compute the final uncertainties associated with the measurements. The dimensional characterization of standards is also carried out. The thesis is based on several S-parameter measurement and uncertainty assessment comparisons. The research work presented in first four chapters has been carried out at Politecnico di Torino and Istituto Nazionale di Ricerca Metrologica (INRiM), Italy. The fifth and sixth chapter described the research activities conducted at National Physical Laboratory (NPL), UK. While the seventh chapter presented the research work carried out at Physikalisch-Technische Bundesanstalt (PTB), Germany. In the first chapter, a general introduction to the VNA measurements and uncertainty assessment is presented. The different measurement errors, calibration standards and the calibration techniques are also described. A brief description is also provided for the classification of the uncertainty components and the S-parameter uncertainty representation. An informal bilateral comparison concerning the S-parameter measurements and uncertainty evaluation at millimeter frequencies (50-110 GHz) is presented in the second chapter. This comparison has been conducted successfully between National Metrology Centre (NMC) A*STAR, Singapore and INRIM, Italy. The aim of this comparison was to assess the compatibility between high frequency measurement systems at both institutes. The electromagnetic computations based on mechanical characterization of the waveguide shim standards are also presented. In the third chapter, a comparison of different S-parameter calibration techniques at millimeter frequencies (75-110 GHz) is described. All the calibration standards were mechanically measured and different calibration techniques were used for tracing S-parameter measurements to the International System of Units (SI). The aim of this comparison was to analyze the efficiency of two different VNA calibration techniques in terms of S-parameter measurements and related uncertainty. The metrological comparison of two different software packages, VNA Tools II and MMS4, is described in fourth chapter. VNA Tools II is developed by Bundesamt für Metrologie (METAS), Switzerland. While, the Multiport Measurement Software version 4 (MMS4) is commercial software package developed by High Frequency Engineering (HFE), Switzerland. Both software packages are based on different mathematical models and have different implementation. However, a comparison is important to validate the reliability of both software packages for the uncertainty contributions considered. This comparison will also allow the metrologists to have more confidence in using these packages for S-parameter measurements and uncertainty analysis. In fifth and sixth chapter, the connection repeatability investigation and calibration comparison of VNA in WR05 waveguide (140-220 GHz) are presented respectively. The connection repeatability investigation is important to analyze the variability of the repeated measurements and flanges' alignment mechanisms especially at these frequencies because of the very small dimensions of the waveguide apertures. In calibration comparison, the behaviour of different calibration techniques is demonstrated. Finally, in the seventh chapter, the suitable verification artefacts to check the performance of VNAs including their applicability to coaxial and waveguide systems are described. The waveguide verification standards considered for analysis are: WR-05 (140-220 GHz) and WR-03 (220-325 GHz) cross-guides and a custom-made WR-03 (220-325 GHz) circular iris section. Moreover, a novel type N coaxial verification standard architecture (DC-18 GHz) based on an air-line has been designed, fabricated and analyze
How to Finance Innovations: Issues and Possible Instruments
Get PDFThis paper discussed the issues and possible instruments that are linked with the financing of innovation activities and projects. The paper elaborated the sources of investment to carry out innovative programs and also demonstrated the importance of government funding and venture capital, especially for the newly establish companies. The paper also discussed the key arguments like the significance of cashflow and role of asymmetric information, and depicted that how these factors can affect while financing an innovative activity or project
On the uncertainty of network analysis methods for the calibration of electrical impedance standards at high frequency
No full textNetwork analysis methods allow to determine the frequency dependence of impedance standards in the so-called LF-RF gap (roughly from 100kHz to 100MHz). Several papers in literature applied the methods on four terminal-pair gas-dielectric capacitors, for which lumped-parameter electrical models have been developed. The methods ask to perform several measurements with a vector network analyzer (VNA), and to perform calculations in the complex field. The uncertainty expression of the measurement outcome becomes an issue, the calculations involved being impossible to be carried out by hand. We propose here to extend a new software (VNA Tools II) by writing dedicated analysis program. The propagation of uncertainty through the measurement model can thus be performed in an automated way by taking into account the strong correlations between the individual VNA readings. Examples of application of the analysis on measurements performed with the so-called S-matrix method are given
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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