1,721,027 research outputs found
Influence of renewable energy potentials on national greenhouse gas reduction strategies
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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
Sekundärdatennutzung bei der ML-gestützten Energieverbrauchsprognose elektrischer Nutzfahrzeuge
No full textElectromobility is considered a key technology for reducing emissions in road transport. A common obstacle to the procuration of electric vehicles is the uncertainty as to whether the individual usage profile can be reliably covered. This can be resolved by forecasting the vehicle's energy consumption. For this purpose, the driving profile that is to be electrified is recorded beforehand to predict the future electric vehicle's energy demand. Based on the results, it is possible to evaluate the electrification potential and, if necessary, identify any required adjustments. To ensure that this individual analysis remains economically viable, the necessary effort must be kept to a minimum.
Electric vehicles' energy demand is highly dependent on ambient conditions, the complete and precise recording of which at the vehicle requires significant resources. One alternative is the use of external data sources (secondary data), through which the required ambient information can be assigned to the driving profile in relation to time and location. So far, however, secondary data has hardly been used in energy consumption prediction, albeit only in a simple way, as there is a lack of clarity about data sources, methods and the necessary effort. Furthermore, prediction models of this kind are mainly used for passenger cars. Applications for commercial vehicles, for which different requirements apply, remain rare.
This dissertation examines the benefits of secondary data when predicting the energy consumption of battery electric commercial vehicles. A methodology is presented for acquiring information on ambient conditions, allowing driving profiles to be enriched with precise secondary data without incurring additional costs. The benefit lies not only in the increase in prediction accuracy: the results show that with the help of secondary data, a high prediction accuracy can be achieved even without access to the vehicle's interfaces. This results in a significant reduction in the measurement effort required for energy consumption prediction whilst only marginally reducing the model quality.Die Elektromobilität gilt als Schlüsseltechnologie zur Reduktion der Emissionen des Straßenverkehrs. Ein häufiges Hemmnis bei der Beschaffung von Elektrofahrzeugen besteht in der Unsicherheit, ob das individuelle Nutzungsprofil verlässlich abgedeckt werden kann. Eine vorab stattfindende Energieverbrauchsprognose kann hier Abhilfe schaffen. Dafür wird das zu elektrifizierende Fahrprofil erfasst, um anschließend den Energiebedarf des künftigen Elektrofahrzeugs vorherzusagen. Anhand der Ergebnisse kann sowohl das Elektrifizierungspotenzial bewertet wie auch gegebenenfalls notwendiger Anpassungsbedarf identifiziert werden. Damit die individuelle Analyse wirtschaftlich sinnvoll ist, darf diese nur einen begrenzten Aufwand erfordern.
Der Energiebedarf von Elektrofahrzeugen ist in hohem Maße von den Umgebungsbedingungen abhängig, deren vollständige und präzise Erfassung am Fahrzeug mit einem hohen Aufwand verbunden ist. Eine Alternative stellt die Nutzung von externen Datenquellen (Sekundärdaten) dar, durch die benötigte Umfeldinformationen dem erfassten Fahrtverlauf zeit- und ortsbezogen zugeordnet werden können. Bislang werden Sekundärdaten bei der Energieverbrauchsprognose kaum oder nur in einfacher Weise genutzt, da Unklarheiten über Datenquellen, Verfahren und den notwendigen Aufwand bestehen. Derartige Prognosemodelle werden zudem überwiegend im PKW-Bereich angewendet. Anwendungen im Nutzfahrzeugsektor, für den abweichende Anforderungen gelten, sind hingegen selten.
In dieser Dissertation wird der Nutzen von Sekundärdaten bei der Energieverbrauchsprognose von batterieelektrischen Nutzfahrzeugen untersucht. Für den Erhalt der Umgebungsbedingungen wird eine Methodik vorgestellt, mit der Fahrprofile ohne Kostenaufwendungen um präzise Sekundärdaten ergänzt werden können. Der Nutzen besteht dabei nicht nur in der Erhöhung der Prognosegüte: Die Ergebnisse zeigen, dass mit Hilfe der Sekundärdaten auch ohne Zugriff auf die Schnittstellen des Fahrzeugs eine hohe Prognosegüte erreicht wird. Daraus folgt eine bedeutende Reduktion des für die Energieverbrauchsprognose notwendigen Messaufwands bei nur geringen Einbußen in der Modellgüte
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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