15 research outputs found
Grambank reveals the importance of genealogical constraints on linguistic diversity and highlights the impact of language loss
While global patterns of human genetic diversity are increasingly well characterized, the diversity of human languages remains less systematically described. Here we outline the Grambank database. With over 400,000 data points and 2,400 languages, Grambank is the largest comparative grammatical database available. The comprehensiveness of Grambank allows us to quantify the relative effects of genealogical inheritance and geographic proximity on the structural diversity of the world's languages, evaluate constraints on linguistic diversity, and identify the world's most unusual languages. An analysis of the consequences of language loss reveals that the reduction in diversity will be strikingly uneven across the major linguistic regions of the world. Without sustained efforts to document and revitalize endangered languages, our linguistic window into human history, cognition and culture will be seriously fragmented.Genealogy versus geography Constraints on grammar Unusual languages Language loss Conclusio
Characterisation and assessment of the harmonic emission of grid-connected photovoltaic systems
Experimental assessment of the waveform distortion in grid-connected photovoltaic installations
This paper provides a multi-faceted view on the characterization of the waveform distortion in grid-connected photovoltaic (PV) plants from experimental results. The focus is set on the characterization of the waveform distortion occurring under different operating conditions in field measurements and laboratory tests. The assessment is carried out by considering the system-based point of view, on the basis of the measurements gathered at the interface between the PV plant and the grid or the supply point in the laboratory. New methodological hints on the formulation of the experimental tests are provided. The results of the waveform distortion analysis for harmonic currents and voltages are compared to the requirements of present power quality standards, indicating that in practical cases the current distortion can be significantly higher than in normal test conditions. Furthermore, the key aspect concerning harmonic and interharmonic modelling of multiple grid-connected PV inverters is addressed. Experimental results on plant configurations with multiple PV inverters show that low-order harmonics sum up almost arithmetically, whereas the higher-order harmonics and the interharmonics sum up in an almost Euclidean wa
Performance of grid-connected photovoltaic systems in fixed and sun-tracking configurations
This paper deals with the performance of grid- connected photovoltaic (PV) systems with parallel-connected converters. The focus of the paper is twofold. The first part concerns the assessment of the energy production and of the operational characteristics of multiple photovoltaic systems in Sun-tracking configurations, comparing their performance to the one of the corresponding fixed PV systems. The second part refers to assessing the harmonic characteristics of the integration of several converters in PV plants of various size. Different indicators are taken into account, including the individual and total harmonic distortion, the harmonic and interharmonic summation ratios at different harmonic orders, as well as the indicators formulated in the IEC Std. 61000-4-7 for group total harmonic distortion (THDG) and subgroup total harmonic distortion (THDS). Results from PV applications in Germany and Italy are shown and discussed
TOMS. Trennstellenoptimierung in Mittelspannungsnetzen Abschlussbericht
Available from TIB Hannover: F98B1444 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman
Ein Verfahren zur Fehlerarterkennung und Impedanzberechnung fuer den Distanzschutz mit Mikrorechnern
TIB: RN 6732 (25/8) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman