1,720,997 research outputs found
Validation of a method to evaluate future impact of road safety interventions, a comparison between fatal passenger car crashes in Sweden 2000 and 2010
No full textWhen targeting a society free from serious and fatal road-traffic injuries, it has been a common practice in many countries and organizations to set up time-limited and quantified targets for the reduction of fatalities and injuries. In setting these targets EU and other organizations have recognized the importance to monitor and predict the development toward the target as well as the efficiency of road safety policies and interventions. This study aims to validate a method to forecast future road safety challenges by applying it to the fatal crashes in Sweden in 2000 and using the method to explain the change in fatalities based on the road safety interventions made until 2010. The estimation of the method is then compared to the true outcome in 2010. The aim of this study was to investigate if a residual of crashes produced by a partial analysis could constitute a sufficient base to describe the characteristics of future crashes. Result: show that out of the 332 car occupants killed in 2000, 197 were estimated to constitute the residual in 2010. Consequently, 135 fatalities from 2000 were estimated by the model to be prevented by 2010. That is a predicted reduction of 41% compared to the reduction in the real outcome of 53%, from 332 in 2000 to 156 in 2010. The method was found able to generate a residual of crashes in 2010 from the crashes in 2000 that had a very similar nature, with regards to crash type, as the true outcome of 2010. It was also found suitable to handle double counting and system effects. However, future research is needed in order to investigate how external factors as well as random and systematic variation should be taken into account in a reliable manner
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
Identifying the Potential of Combined Road Safety Interventions - A Method to Evaluate Future Effects of Integrated Road and Vehicle Safety Technologies
No full textHealth loss in the road transport system is one of the leading global public health problems with approximately 1.3 million people killed annually. In order to have a systematical approach to improved road safety, it has become common practice to form road safety management policies that include target setting and evaluation. The overall aim of this thesis was to facilitate road safety management by developing a new method to guide stakeholders with decisions on the most effective interventions to improve road safety, or in the design of safety innovations.In this thesis, a new method to identify the potential of combined road safety interventions was developed and validated. Crashes were studied from a system’s approach perspective, and the integrated safety chain was used to derive a residual of crashes from a baseline based on assumptions regarding the progress of Safety Performance Indicators over the period studied. The characteristics of the residual fatal crashes in 2020 were then described and analyzed to identify future safety gaps. A validation of the method was conducted by taking into account actual interventions implemented between 2000 and 2010 and by reducing the fatalities in 2000 to a residual of crashes in 2010 and then comparing this to the true outcome of 2010. It was concluded that the method was found to give an overall valid explanation for the reduction of fatalities from 2000 to 2010.The main advantage of this method compared to previous methods is the ability to describe the characteristics of future crashes, and what measures would be effective in reducing them. Single vehicle and head-on crashes were estimated to be reduced most significantly from 2000 to 2010, largely as a result of the installation of median barriers and the fitment of Electronic Stability Control. In two studies, effect estimates of pedestrian friendly car fronts and Autonomous Emergency Braking (AEB) fitted on Heavy Goods Vehicles in head-on crashes were derived and these estimates can be applied in the method in future. It was also concluded that positive system effects can emerge between road and vehicle safety technologies. Speed management can enhance the performance of pedestrian protection which will be important for increasing safety for vulnerable road users. In addition, it was found that the overall effectiveness of AEB would increase if the proportion of loss-of-control scenarios is minimalized and that AEB could be very helpful for increasing the compatibility between passenger cars and Heavy Goods Vehicles.This thesis presents a new approach to evaluating future effects of integrated road and vehicle safety technologies. It can be summarized as; 1 – Highlight future potentials and safety gaps, 2 – Define and refine technological innovations and 3 – Guiding integrated interventions. It is recommended that the evolution of the transport system is taken into account when estimating the benefits of future technologies. Road and vehicle safety interventions should be designed in collaboration with stakeholders and combined in the best possible way in order to create positive system effects. There is also a need for accurate effect estimates as they form essential tools in the road safety management process
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
Identifying the Potential of Combined Road Safety Interventions - A Method to Evaluate Future Effects of Integrated Road and Vehicle Safety Technologies
No full textHealth loss in the road transport system is one of the leading global public health problems with approximately 1.3 million people killed annually. In order to have a systematical approach to improved road safety, it has become common practice to form road safety management policies that include target setting and evaluation. The overall aim of this thesis was to facilitate road safety management by developing a new method to guide stakeholders with decisions on the most effective interventions to improve road safety, or in the design of safety innovations.In this thesis, a new method to identify the potential of combined road safety interventions was developed and validated. Crashes were studied from a system’s approach perspective, and the integrated safety chain was used to derive a residual of crashes from a baseline based on assumptions regarding the progress of Safety Performance Indicators over the period studied. The characteristics of the residual fatal crashes in 2020 were then described and analyzed to identify future safety gaps. A validation of the method was conducted by taking into account actual interventions implemented between 2000 and 2010 and by reducing the fatalities in 2000 to a residual of crashes in 2010 and then comparing this to the true outcome of 2010. It was concluded that the method was found to give an overall valid explanation for the reduction of fatalities from 2000 to 2010.The main advantage of this method compared to previous methods is the ability to describe the characteristics of future crashes, and what measures would be effective in reducing them. Single vehicle and head-on crashes were estimated to be reduced most significantly from 2000 to 2010, largely as a result of the installation of median barriers and the fitment of Electronic Stability Control. In two studies, effect estimates of pedestrian friendly car fronts and Autonomous Emergency Braking (AEB) fitted on Heavy Goods Vehicles in head-on crashes were derived and these estimates can be applied in the method in future. It was also concluded that positive system effects can emerge between road and vehicle safety technologies. Speed management can enhance the performance of pedestrian protection which will be important for increasing safety for vulnerable road users. In addition, it was found that the overall effectiveness of AEB would increase if the proportion of loss-of-control scenarios is minimalized and that AEB could be very helpful for increasing the compatibility between passenger cars and Heavy Goods Vehicles.This thesis presents a new approach to evaluating future effects of integrated road and vehicle safety technologies. It can be summarized as; 1 – Highlight future potentials and safety gaps, 2 – Define and refine technological innovations and 3 – Guiding integrated interventions. It is recommended that the evolution of the transport system is taken into account when estimating the benefits of future technologies. Road and vehicle safety interventions should be designed in collaboration with stakeholders and combined in the best possible way in order to create positive system effects. There is also a need for accurate effect estimates as they form essential tools in the road safety management process
A Method to Identify Future Potential of Vehicle Safety Technology
No full textIn the design of a safe road transport system there is a need to better understand the safety challenges lying ahead. One way of doing that is to evaluate safety technology with retrospective analysis of real world crashes. However, by using retrospective data there is the risk of adapting safety innovations to scenarios irrelevant in the future. Also, challenges arise as safety interventions do not act alone but are rather interacting components in a complex road transport system and there exists no linearity between the development of Safety Performance Indicators in traffic and in the final outcome in terms of health losses.
This thesis is based on two papers from studies aiming to increase the knowledge in this field by (1) developing and applying a new method to identify future potential of vehicle safety technology in Sweden, and (2) estimate the potential benefits of Autonomous Emergency Braking (AEB) in head-on crashes between passenger cars and heavy-goods vehicles. The first study relates to the need for new prediction models, while the second relates to the need for further understanding how different crash scenarios determines the input and output in different parts in the chain of events leading to a crash, e.g. the integrated safety chain, and thereby affects the performance of safety systems.
The key point in study 1 was to project the integrated safety chain in crashes of today into the crashes for a given time in the future. Assumptions on the implementation of safety technologies were made as applied to fatal passenger-car crashes of today. It was estimated which crashes would be prevented and the residual were analyzed to identify the characteristics of future crashes. The study predicts that the number of car occupants killed would be reduced by 53% from 2010 to 2020. Through this new method, valuable information regarding the characteristic of the future crashes could also be found.
In study 2 calculations of the available time for AEB depending on crash scenario were done in order to estimate the potential benefits of AEB. The findings indicates that there is a great safety potential in applying AEB in head-on scenarios even late in the integrated safety chain, when the collision is no longer avoidable by steering. It also confirmed that the available time for AEB, and thereby the effect of AEB in delta-v reduction, is highly dependent on the scenarios prior to the point of braking.
Application of the combined results from paper 1 and paper 2 can be exemplified in that paper 1 predicts a reduction of loss-of-control scenarios and paper 2 shows that this specific scenario provides the shortest time available for autonomous emergency braking. Thus, there are indications that AEB could have a greater safety potential in the future as loss-of-control scenarios are decreasing over time. Even though more knowledge is required, these interactions and possible systems effects highlights the potential in having an holistic approach when evaluating vehicle safety technologies and their future benefits
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