1,720,965 research outputs found
Analysis of VECTO data for Heavy-Duty Vehicles (HDV) CO2 emission targets
Full text linkThis report summarises the analysis done on the data provided to the European Commissions’ Joint Research Centre by the Heavy Duty Vehicle manufacturers about the 2016 Heavy Duty Vehicles’ fleet composition and CO2 emissions performance. The results comprise of key metrics and a representative fleet-wide CO2 emissions baseline distribution for the year 2016 which were key inputs to the impact assessment study that supported the European Commission's proposal for new Heavy-Duty Vehicle CO2 standards in Europe. All datasets were checked for quality and errors and were validated against similar data calculated by external parties. CO2 emissions values were normalised to a common reference basis and CO2 distributions were produced for the four vehicle categories of interest. The normalisation process led to lower fleet-wide CO2 emissions, an important observation for defining realistic CO2 limits for the post-2020 period.JRC.C.4 - Sustainable Transpor
Report on VECTO Technology Simulation Capabilities and Future Outlook
Full text linkThe European Commission is developing the Vehicle Energy Consumption Calculation Tool (VECTO) for Heavy Duty Vehicle CO2 certification purposes. VECTO is a vehicle simulation tool tailored to estimate CO2 emissions from heavy-duty vehicles of different categories, sizes and technologies. Further development and optimization of VECTO and the CO2 certification methodology requires assessing their capacity to properly simulate specific vehicle technologies and gathering additional feedback on the possibility to capture future technologies which are expected to be deployed on heavy-duty vehicles in the years to come. In order to investigate the VECTO capabilities and performance a dedicated questionnaire was formulated and distributed to various stakeholders. The technologies under investigation were previously identified through a literature review. The feedback received clearly pointed out the technologies that can be properly simulated by VECTO, which constituted an important part of the initial technology list, pointing out that VECTO and the accompanying certification methodology have reached a good level of maturity. The responses provided also some initial feedback on the implementation approach for the technologies which are not properly captured at the moment. The latter were separated into three groups based on the type of work that is required for including them in the certification methodology which could relate either to the development of the VECTO software or further expansion-specialization of CO2 certification methodology or a combination of the two. The current report presents the findings of the survey and outlines possible future steps for the further development of VECTO software and the accompanying certification methodologyJRC.C.4 - Sustainable Transpor
Ανάπτυξη μεθοδολογίας για τον προσδιορισμό των εκπομπών CO2 επιβατηγών οχημάτων στα πλαίσια των εκπομπών σε πραγματικές συνθήκες
No full textMany regions around the globe have implemented mandatory CO2 emission targets for both light and heavy-duty vehicles. These targets are monitored through certification approaches, primarily relying on laboratory measurements conducted using chassis dynamometers. However, there's a notable discrepancy between these laboratory-certified values and real-world on-road performance due to various factors affecting fuel and energy consumption during actual operation. To address this challenge, the Thesis aims to develop a methodology based on vehicle simulation to predict representative on-road fuel and energy consumption values using limited data. This approach includes incorporating provisions of regulations, such as the On-Board Fuel Consumption Meter (OBFCM), to enhance calculations for specific vehicles to improve and enhance the accuracy of simulations. The Thesis is structured into several chapters, beginning with the introduction that outlines the objectives and scope; to create a tool capable of simulating vehicle emissions using limited input data. Subsequent chapters delve into the background of fuel consumption parameters, vehicle measurements for model validation and verification, simulation model development, model adjustment for improved accuracy, and potential applications of the developed methodology. Key findings include the identification of factors contributing to the discrepancy between certification and on-road values, such as vehicle mass, aerodynamic resistance, rolling resistance, temperature, driving behaviour, and traffic conditions. The simulation model development involves grouping vehicles into clusters based on powertrain and engine capacity, simulating generic vehicles under various conditions, and validating the model against on-road measurements. Model adjustment strategies include transitioning from a vehicle-generic to a vehicle- specific approach to reduce discrepancies in fuel and electric energy consumption calculations. The simulation model demonstrates its versatility and effectiveness in raising user awareness and promoting energy-efficient vehicles through its integration into the MILE21 – LIFE project. In addition, it has demonstrated its capability to be deployed in other regions such as in the USA. The Thesis concludes with an evaluation of the simulation model's performance and suggestions for future research to further enhance its accuracy and applicability. Areas for improvement include investigating the cold start effect, evaluating the impact of auxiliary usage, refining vehicle-specific parameters using OBFCM data, capturing also pollutant emissions, and exploring vehicle-to-platform communication for monitoring and automatically updating the simulation model. In summary, the developed simulation model successfully addresses the challenges of predicting on-road fuel and energy consumption values and offers valuable insights for institutions and research organizations focused on mitigating emissions and raising user awareness.Πολλές περιοχές σε όλο τον κόσμο έχουν εφαρμόσει υποχρεωτικούς στόχους εκπομπών CO2 τόσο για τα ελαφρά όσο και για τα βαρέα οχήματα. Οι στόχοι αυτοί παρακολουθούνται μέσω των διαδικασιών πιστοποίησης των οχημάτων, οι οποίες βασίζονται κυρίως σε εργαστηριακές μετρήσεις που πραγματοποιούνται με τη χρήση δυναμομετρικής πέδης. Ωστόσο, υπάρχει μία σημαντική απόκλιση μεταξύ των εργαστηριακά μετρημένων τιμών και των πραγματικών τιμών στον δρόμο, λόγω διαφόρων παραγόντων που επηρεάζουν την κατανάλωση καυσίμου και ηλεκτρικής ενέργειας. Για την αντιμετώπιση αυτού του προβλήματος, η Διδακτορική Διατριβή στοχεύει στην ανάπτυξη μίας μεθοδολογίας που βασίζεται στην προσομοίωση οχημάτων για την πρόβλεψη αντιπροσωπευτικών τιμών κατανάλωσης καυσίμου και ενέργειας σε πραγματικές συνθήκες λειτουργίας, χρησιμοποιώντας περιορισμένα δεδομένα. Η προσέγγιση αυτή περιλαμβάνει την ενσωμάτωση διατάξεων της Ευρωπαϊκής Νομοθεσίας, όπως το On-Board Fuel Consumption Meter (OBFCM), για τη βελτίωση των υπολογισμών για συγκεκριμένα οχήματα. Η Διδακτορική Διατριβή διαρθρώνεται σε κεφάλαια, ξεκινώντας με την εισαγωγή που περιγράφει τους στόχους και το πεδίο εφαρμογής: τη δημιουργία ενός εργαλείου ικανού να προσομοιώνει τις εκπομπές οχημάτων χρησιμοποιώντας περιορισμένα δεδομένα εισόδου. Τα επόμενα κεφάλαια εμβαθύνουν στο υπόβαθρο των παραμέτρων κατανάλωσης καυσίμου, στις μετρήσεις οχημάτων για την επικύρωση και την επαλήθευση του μοντέλου, στην ανάπτυξη του μοντέλου προσομοίωσης, στην προσαρμογή του μοντέλου για βελτιωμένη ακρίβεια και στις πιθανές εφαρμογές της μεθοδολογίας που αναπτύχθηκε. Τα βασικά ευρήματα περιλαμβάνουν τον προσδιορισμό των παραγόντων που συμβάλλουν στην απόκλιση μεταξύ των τιμών πιστοποίησης και των τιμών στο δρόμο, όπως η μάζα του οχήματος, η αεροδυναμική αντίσταση, η αντίσταση κύλισης, η θερμοκρασία, η οδηγική συμπεριφορά και οι συνθήκες κυκλοφορίας. Η ανάπτυξη του μοντέλου προσομοίωσης περιλαμβάνει την ομαδοποίηση των οχημάτων σε κατηγορίες με βάση το σύστημα μετάδοσης κίνησης και τον κυβισμό του κινητήρα, την προσομοίωση γενικών οχημάτων υπό διάφορες συνθήκες και την επικύρωση του μοντέλου με μετρήσεις στο δρόμο. Οι στρατηγικές προσαρμογής του μοντέλου περιλαμβάνουν τη μετάβαση από μια προσέγγιση γενικού οχήματος σε μια προσέγγιση συγκεκριμένου οχήματος για τη μείωση των αποκλίσεων στους υπολογισμούς κατανάλωσης καυσίμου και ηλεκτρικής ενέργειας. Το μοντέλο προσομοίωσης αποδεικνύει την ευελιξία και την αποτελεσματικότητά του στην ευαισθητοποίηση των χρηστών και την προώθηση ενεργειακά αποδοτικών οχημάτων μέσω της ενσωμάτωσής του στο έργο MILE21 – LIFE. Επιπλέον, έχει αποδείξει την ικανότητα να εφαρμοστεί και σε οχήματα άλλως περιοχών όπως οι ΗΠΑ. Η Διδακτορική Διατριβή ολοκληρώνεται με την αξιολόγηση των επιδόσεων του μοντέλου προσομοίωσης και με προτάσεις για μελλοντική έρευνα για την περαιτέρω ενίσχυση της ακρίβειας και των δυνατοτήτων εφαρμογής του. Τα προτεινόμενα πεδία βελτίωσης περιλαμβάνουν τη διερεύνηση του φαινομένου της ψυχρής εκκίνησης, την αξιολόγηση της επίδρασης της χρήσης των περιφερειακών συστημάτων όπως ο κλιματισμός, την ανάπτυξη εξειδικευμένων παραμέτρων υπολογισμού για κάθε όχημα με τη χρήση δεδομένων OBFCM, τον υπολογισμό επίσης των εκπομπών ρύπων και τη διερεύνηση της επικοινωνίας οχήματος-πλατφόρμας για την παρακολούθηση και την αυτόματη ενημέρωση του μοντέλου προσομοίωσης. Συνοψίζοντας, το μοντέλο προσομοίωσης εκπληρώνει με επιτυχία τους στόχους της πρόβλεψης των τιμών κατανάλωσης καυσίμου και ενέργειας σε πραγματικές συνθήκες και αποτελεί ένα χρήσιμο εργαλείο για ινστιτούτα και ερευνητικούς οργανισμούς που επικεντρώνονται στις εκπομπές CO2 και την ευαισθητοποίηση των χρηστών
Future CO2 reducing technologies in VECTO
Full text linkThe software tool VECTO is used to determine the energy demand, fuel consumption and CO2 emissions of new heavy-duty vehicles. The tool takes into account the relevant vehicle component technologies that affect fuel consumption and CO2 emissions and should be updated when new relevant technologies are brought to the market. This work presents the results of a survey investigating the capability of VECTO to simulate new vehicle technologies, along with CO2 reduction potential and the expected penetration rate in the market of these technologies. An in-depth analysis of these new technologies is presented in this work.
Many of the technologies demonstrating high potential in reducing CO2 and market uptake in the near future (e.g. aero devices for trailers and bodies and hybrid electric powertrains) are currently being implemented in VECTO. The next steps can include zero-emission vehicles, such as fuel cell vehicles, and technologies that could be easily implemented.JRC.C.4 - Sustainable Transpor
Real world emissions performance of heavy-duty Euro VI diesel vehicles
No full textDespite that Heavy-Duty Vehicles (HDVs) represent a small part of the overall vehicle population they have been identified as one of the most important contributors to air pollution. This is one of the reasons why HDV emissions regulations are becoming more and more stringent worldwide. Following this trend, Europe introduced the Euro VI standard which includes more stringent emission limits for hydrocarbons, PM and NOx, while for the first time limits for solid PN and NH3 were set. At the same time increased concern regarding greenhouse gas emissions led to a series of initiatives including HDVs CO2 certification and monitoring with the latest being the submission of a proposal for CO2 emission targets for 2025 and 2030. Despite the general concern, published data regarding Euro VI HDV emissions are scarce, while real-world emission factor measurements of regulated and unregulated pollutants are even more difficult to find. The main objective of this paper is to present real-world diesel Euro VI HDVs emissions of both gaseous pollutants and solid PN. For that reason five HDVs, including four trucks and one bus, were tested on-road under typical driving conditions. A breakdown of the emissions to low, medium, and high speed conditions was also performed with the aim investigating the performance of aftertreatment systems under different speed conditions. All tested vehicles performed better compared to older technology diesel HDVs, thus reflecting the technological improvements introduced over the last years. However, relatively high emissions were observed for some of the pollutants over low speed phases due to reduced effectiveness of the corresponding emission control systems. Calculated emission factors were also compared to existing emission inventories and good correlation was found for NOx, CO2 and solid PN emissions.JRC.C.4 - Sustainable Transpor
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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