Search results for "Definition"
showing 10 items of 217 documents
An enhanced approach based on IEEE 1459 for the detection of disturbing loads in distorted and unbalanced three-phase power systems
2009
This paper presents an enhanced approach for the detection of disturbing loads in distorted and/or unbalanced three-phase power systems in both cases of three and four-wires. It is based on the IEEE Std. 1459-2000 effective apparent power resolution and it requires only the separation of the fundamental components of voltage and current from the remaining harmonic content. In the paper, the formulation of the novel approach is given and some simulation results are presented.
Disturbing loads identification in power systems: a single-point time-domain method based on IEEE 1459-2000
2009
This paper presents a single-point method for the identification of prevailing disturbing loads in power systems for both single-phase and three-phase applications downstream or upstream from the metering section. It is based on the simultaneous measurement of three nonactive power quantities, which are based on the IEEE Std. 1459-2000 approach. The proposed method is only based on the separation of the fundamental components from the harmonic content of voltage and current; thus, it does not require any spectral analysis of the voltages and current. In this paper, the formulation of the proposed method and its time-domain implementation are described; moreover, some simulation results are …
What is a tree in the Mediterranean Basin hotspot? A critical analysis
2019
Background: Tree species represent 20% of the vascular plant species worldwide and they play a crucial role in the global functioning of the biosphere. The Mediterranean Basin is one of the 36 world biodiversity hotspots, and it is estimated that forests covered 82% of the landscape before the first human impacts, thousands of years ago. However, the spatial distribution of the Mediterranean biodiversity is still imperfectly known, and a focus on tree species constitutes a key issue for understanding forest functioning and develop conservation strategies. Methods: We provide the first comprehensive checklist of all native tree taxa (species and subspecies) present in the Mediterranean-Europ…
Ocho notas sobre la Casa Farnsworth de Ludwig Mies van der Rohe
2020
Mies was in the top of his career when he built the Farnsworth House. The analysis of this work shows some characteristics of his architectural thought: the relationships between architecture and nature, the definition of the pavilion type, his concept of architectural space, the role of structure and limits, the idea free plan and the meaning of construction
Coordinate compounding in English and Spanish
2011
Coordinate compounding is a process which has been only sporadically considered in wordformation studies on Germanic and Romance languages. In this paper, we compare the situation in English with that in Spanish as far as formal structure and semantics are concerned. To this end, an operational definition of coordinate compounding is first provided, after which a semantic classification of coordinate compounds is developed. For each type, variants are discussed, representative examples are provided, and similarities and dissimilarities between the two languages are highlighted. We finish by raising the issues of recursiveness and productivity in coordinate compounding and we examine the pos…
From corona virus to corona crisis : the value of an analytical and geographical understanding of crisis
2020
Abstract The term ‘crisis’ is omnipresent. The current corona virus pandemic is perceived as the most recent example. However, the notion of crisis is increasingly deployed as a signifier of relevance, rather than as an analytical concept. Moreover, human geography has so far little contributed to the interdisciplinary crisis research field which is fixated on the temporal aspects of crisis but neglects its spatiality. Against this background, the first aim of the paper is to demonstrate the value of thinking about crisis analytically. Therefore, we introduce theoretical knowledge developed within a recently emerging literature on crisis management. Second, we demonstrate the relevance of i…
Extensional flow of HDPE/LDPE blends
1982
Elongational viscosity data, obtained through the converging flow analysis by Cogswell, are presented for two types of HDPE/LDPE blends at various compositions and different temperatures. The results relative to the homopolymer parents compare favourably with literature data obtained also with different and more sophisticated techniques. Those relative to blends show peculiar features for the two cases: when the newtonian viscosity of the LDPE is higher all the blends show a behaviour typical of the LDPE with a maximum in η el /η0 enhanced at small percentage of HDPE; when the newtonian viscosity of the LDPE is similar to that of the HDPE there is only a gradual change in the properties.
What does it mean to be visually literate? Examination of visual literacy definitions in a context of higher education
2018
Full Article Figures & data References Citations Metrics Reprints & Permissions Get access Abstract Competency in visual literacy (VL) is crucial for effective visual communication, and thus for living and working in a visually saturated environment. However, VL across disciplines is still marginalized in higher education curricula. This tendency is partly caused by the lack of knowledge and agreement on what it means to be visually literate. This study juxtaposes and evaluates 11 VL definitions, selected as the most relevant for higher education practitioners and coined from 1969 (the first one) to 2013 (the most recent one). The study further proposes three lists of VL skills with themati…
Tensor products, multiplications and Weyl’s theorem
2005
Tensor productsZ=T 1⊗T 2 and multiplicationsZ=L T 1 R T 2 do not inherit Weyl’s theorem from Weyl’s theorem forT 1 andT 2. Also, Weyl’s theorem does not transfer fromZ toZ*. We prove that ifT i,i=1, 2, has SVEP (=the single-valued extension property) at points in the complement of the Weyl spectrumσ w(Ti) ofT i, and if the operatorsT i are Kato type at the isolated points ofσ(Ti), thenZ andZ* satisfy Weyl’s theorem.