16 research outputs found
Towards a quality metric for dense light fields.
Light fields become a popular representation of three-dimensional scenes, and there is interest in their processing, resampling, and compression. As those operations often result in loss of quality, there is a need to quantify it. In this work, we collect a new dataset of dense reference and distorted light fields as well as the corresponding quality scores which are scaled in perceptual units. The scores were acquired in a subjective experiment using an interactive light-field viewing setup. The dataset contains typical artifacts that occur in light-field processing chain due to light-field reconstruction, multi-view compression, and limitations of automultiscopic displays. We test a number of existing objective quality metrics to determine how well they can predict the quality of light fields. We find that the existing image quality metrics provide good measures of light-field quality, but require dense reference light-fields for optimal performance. For more complex tasks of comparing two distorted light fields, their performance drops significantly, which reveals the need for new, light-field-specific metrics
Roflumilast in moderate-to-severe chronic obstructive pulmonary disease treated with longacting bronchodilators: two randomised clinical trials
Background Patients with chronic obstructive pulmonary disease (COPD) have few options for treatment. The efficacy and safety of the phosphodiesterase-4 inhibitor roflumilast have been investigated in studies of patients with moderate-to-severe COPD, but not in those concomitantly treated with longacting inhaled bronchodilators. The effect of roflumilast on lung function in patients with COPD that is moderate to severe who are already being treated with salmeterol or tiotropium was investigated. Methods In two double-blind, multicentre studies done in an outpatient setting, after a 4-week run-in, patients older than 40 years with moderate-to-severe COPD were randomly assigned to oral roflumilast 500 mu g or placebo once a day for 24 weeks, in addition to salmeterol (M2-127 study) or tiotropium (M2-128 study). The primary endpoint was change in prebronchodilator forced expiratory volume in 1s (FEV(1)). Analysis was by intention to treat. The studies are registered with ClinicalTrials.gov, number NCT00313209 for M2-127, and NCT00424268 for M2-128. Findings In the salmeterol plus roflumilast trial, 466 patients were assigned to and treated with roflumilast and 467 with placebo; in the tiotropium plus roflumilast trial, 371 patients were assigned to and treated with roflumilast and 372 with placebo. Compared with placebo, roflumilast consistently improved mean prebronchodilator FEV(1) by 49 mL (p<0.0001) in patients treated with salmeterol, and 80 mL (p<0.0001) in those treated with tiotropium. Similar improvement in postbronchodilator FEV(1) was noted in both groups. Furthermore, roflumilast had beneficial effects on other lung function measurements and on selected patient-reported outcomes in both groups. Nausea, diarrhoea, weight loss, and, to a lesser extent, headache were more frequent in patients in the roflumilast groups. These adverse events were associated with increased patient withdrawal. Interpretation Roflumilast improves lung function in patients with COPD treated with salmeterol or tiotropium, and could become an important treatment for these patients
The Institutionalization of Scientific Information: A Scientometric Model (ISI-S Model)
published or submitted for publicatio
0 Elsevier Science Publishers B.V.. 1990 BIBLIOMETRIC ANALYSIS OF PUBLICATION ACTIVITY OF A SCIENTIFIC
&quot;Little can be done to affect the least productive, and nothing need be done that could affect the mos
The evaluation of research by scientometric indicators
Aimed at academics, academic managers and administrators, professionals in scientometrics, information scientists and science policy makers at all levels. This book reviews the principles, methods and indicators of scientometric evaluation of information processes in science and assessment of the publication activity of individuals, teams, institutes and countries. It provides scientists, science officers, librarians and students with basic and advanced knowledge on evaluative scientometrics. Especially great stress is laid on the methods applicable in practice and on the clarification of quantitative aspects of impact of scientific publications measured by citation indicators
Patent Indicators Characterizing Information Flow Between Countries
49-59Patents like papers are carriers of
original information. Some indicators have been introduced to characterize
patenting relations between countries. The Foreign Patent Penetration (FPP)
indicator e.g. relates the percentage share of patents in a given country
granted to patentees from a group of high income economies (ECP) to the total
of ECP resident patents. Share of patents granted to a given country in ECP
countries was related to the total of non-resident patents granted in ECP
countries (FPI, Foreign Patent Integration). The indicators reveal that the
patenting activity of Japan is extremely high, while the interest of high
income economies towards the Japanese patent market is very modest Integration
of the formerly centralized East European economies into the world patenting
system was found to be low (except for Hungary and Poland in certain aspects). GDP
and WIP (which represents the scientific
information production of countries) were
found to be correlated with the patent
indicators