1,720,957 research outputs found
Effects of energy efficiency measures on building performance: an analysis in seven European cities
No full textThis work presents the energy performance analysis of an autarkic residential building, located in the
suburb of L’Aquila, in central Italy. The analysis is performed via a calibrated dynamic thermal model, carried out
with EnergyPlusTM engine coupled with DesignBuilder. The aim of this study is the further understanding of the
optimization margins of the energy self-sufficient building by considering different Energy Efficiency Measures
and the effects obtainable in different climatic conditions. Four Italian cities and three European capitals are
considered, in addition to different scenarios, characterized by various technological plants. In fact, a significant
difference between the high efficiency of the envelope, and the poor performance of the heating system was
observed. The results highlighted the remarkable energy performance optimization of the analyzed building,
although the effects of the Energy Efficiency Measures showed notable differences between colder and warmer climates
Room and window geometry influence for daylight harvesting maximization – Effects on energy savings in an academic classroom
Full text linkLighting systems have a fundamental role for the overall buildings energy consumption. Therefore, remarkable efforts are required for optimizing the lighting systems energy use and for finding new daylight harvesting solutions. In this paper, the impacts on daylight harvesting provided by different room and window geometries and their effects on energy savings are presented. An academic classroom with only one window is chosen as case study and it is supposed that the window orientation is modified according to the four cardinal points. A climate-based approach was chosen for the multiple simulations, carried out via DIVA software, by assuming: square and rectangular classroom geometries with the same total area; square and rectangular window shapes having Window to Floor Ratios (WFRs) equal to 8% and 12%; two different dimmable lighting systems, in order to quantify the energy savings, by considering fluorescent and LED dimmable lamps. The daylight analysis, performed by evaluating both the Daylight Factor (DF) and the Daylight Autonomy (DA), showed that room and window geometries have high influence on daylight harvesting maximization, allowing remarkable energy savings (up to 48.5%) with respect to non-dimmable lighting system. In particular, the best energy result, equal to 467.5 kWh/yr, was obtained with rectangular room and window geometries coupled with LED lamps and WFR equal to 12%
Hidden Grid Background Oriented Schlieren in studying convective flows
No full textIn this paper, we present a new BOS (Background Oriented Schlieren), based on a hidden grid, for studying heat flows. In the setup, we record a grid-based intensity pattern whose phase map carries information about the temperature gradient. The background (undistorted) pattern is hidden in the light source. Quantitative analysis is obtained by a windowed Fourier transform approach. Some experimental results are given to demonstrate the feasibility of the technique
Digital Multi-Probe Temperature Monitoring System for Long-Term on Field Measurements
Full text linkIn this work, we present a flexible and multi-probe temperature measurement system, suitable for real time monitoring and long-term applications. The proposed sensor system allows to investigate the thermal performance of different environments such as building areas, walls or external places. The equipment has been characterized both at device and system levels and validated through experimental tests through a comparison with different sensors. The conceived system consists of a control unit with a microcontroller, a user interface and an internal recording section for data storage and management, and digital temperature sensors with a 12-bit resolution, whose number can be freely defined, having the system a modular architecture. The low-cost and open-source characteristics, beyond of its flexibility and capability to manage several sensors placed also very far from the control unit (up to 500 m), make the proposed solution a suitable candidate to be used for practical applications that require on-field measurements
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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