1,720,952 research outputs found
Probe data from consumer GPS navigation devices for the analysis of controlled intersections
No full textProbe data from consumer GPS navigation devices provides a network-wide and costefficient data source for measuring vehicle movements, whereas experimental studies have been confined to small datasets. Data collection from road-side sensors can provide similar information but is expensive and requires high maintenance expenditures. This paper presents the results of intersection performance measurement using a large probe dataset from consumer GPS navigation devices. The measurement of delay and turning movements is compared with loop detection traffic counts and delay estimation from stationary sensors in the Dutch city of Delft. Turning movements are measured with an average error of 1.35% to 3.76%. The results show that the data is beneficial for a quick assessment of the delay and turning movements at intersections, especially intersections where data from stationary detectors is not easily accessible.Transport & PlanningCivil Engineering and Geoscience
The Influence of Spatially Varying Supply on Coastal Aeolian Transport: A Field Experiment
No full textSupply-limiting factors, like moisture content and sediment armoring,influence coastal aeolian sediment transport and subsequently dune evolutionsignificantly. We organized a 6-week field experiment on the influence ofspatiotemporal variations in supply on coastal aeolian sediment transport at theSand Motor, The Netherlands. Due to the presence of a strongly curved coastlineand complex intertidal bathymetries, a large spatial variation in supply is to beexpected at the Sand Motor, which makes the area particularly suitable for a fieldexperiment on this subject. Preliminary results show that not the largest surfacearea of sand, nor the biggest fetch or the most severe storm result in significantaeolian sediment transport events, but persistent moderate winds over largeintertidal beaches are the key to coastal aeolian transport and subsequently duneevolution.Coastal Engineerin
Navigating for new traffic solutions: The use of probe data from consumer GPS navigation devices for the analysis of controlled intersections
No full textProbe data from consumer GPS navigation devices provides a network-wide and cost-efficient data source for measuring vehicle movements. The measurement of traffic volume, route choice and delay on intersections is needed for efficient intersection control. Data collection from road-side sensors can provide this information but is expensive and requires high maintenance expenditures. Probe vehicle data provides an interesting alternative although experimental studies have been confined to small datasets. This study presents the results of intersection performance measurement using a large probe dataset from consumer GPS navigation devices. In this paper the delay and route choice are derived from probe data collected with consumer GPS navigation devices at two intersections in the Dutch city of Delft. The objective is to evaluate the accuracy of probe data collected with consumer GPS navigation devices for the measurement of delay and route choice at intersections. The measurements are compared with loop detection traffic counts and delay estimation from stationary sensors. Probe data from consumer GPS navigation devices provides a suitable data source for the determination of route choice and delay at two test case intersections if a sufficient sample size is available. Route choice is measured with an average error of 1.35% to 3.76%. This new data source is beneficial for a quick assessment of the delay and route choice at intersections, including intersections without fixed detectors or where data from stationary detectors is not easily accessible.Transport and PlanningTransport & PlanningCivil Engineering and Geoscience
Is exercise training safe and effective for ALL heart failure patients: A retrospective service evaluation of a hospital based cardiac rehabilitation programme
Get PDFThe main purpose of this study was to investigate whether exercise training is safe and effective for all classifications of heart failure, female and elderly (70 years and above) heart failure patients and also those heart failure patients with significant co-morbidity. Much of the research into exercise training and heart failure has been carried out on middle aged men in NYHA II-III classification of heart failure who have no other significant co-existing conditions. This is not reflective of the population of heart failure patients in general. The cardiac rehabilitation records (n=1000) of heart failure patients who had attended an exercise programme at a hospital based NHS service over a period of ten years were retrospectively evaluated to investigate the safety and efficacy of exercise training. Analysis of baseline statistics and repeated outcome measures were used to investigate the significance of the service and to ascertain where similarities and differences lay with the research. 74% were male, the age range was 17-90 years and 52% of patients had one or more significant co-morbidity. The acute event incidence was recorded at four per 1000 patients. NYHA I patients, female, elderly heart failure patients and those with significant co-morbidity showed significant improvements in functional capacity and quality of life measures with exercise training (p< 0.05). However no conclusion on the effectiveness of exercise could be drawn for NYHA IV heart failure patients due to insufficient recorded data and reduced adherence to exercise sessions for this group. A hospital based exercise programme, therefore may not be the most appropriate setting for the NYHA IV patient. This study supports previous research of the benefit of exercise training in heart failure but broadens it further to show that exercise is safe for all heart failure patients and is also effective for all heart failure patients with the exception of NYHA IV patients where further investigation is needed
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
- …
