A novel method for subjective picture quality assessment and further studies of HDTV formats

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ IEEE 2008.This paper proposes a novel method for the assessment of picture quality, called triple stimulus continuous evaluation scale (TSCES), to allow the direct comparison of different HDTV formats. The method uses an upper picture quality anchor and a lower picture quality anchor with defined impairments. The HDTV format under test is evaluated in a subjective comparison with the upper and lower anchors. The method utilizes three displays in a particular vertical arrangement. In an initial series of tests with the novel method, the HDTV formats 1080p/50,1080i/25, and 720p/50 were compared at various bit-rates and with seven different content types on three identical 1920 times 1080 pixel displays. It was found that the new method provided stable and consistent results. The method was tested with 1080p/50,1080i/25, and 720p/50 HDTV images that had been coded with H.264/AVC High profile. The result of the assessment was that the progressive HDTV formats found higher appreciation by the assessors than the interlaced HDTV format. A system chain proposal is given for future media production and delivery to take advantage of this outcome. Recommendations for future research conclude the paper

Image interpolation using Shearlet based iterative refinement

This paper proposes an image interpolation algorithm exploiting sparse representation for natural images. It involves three main steps: (a) obtaining an initial estimate of the high resolution image using linear methods like FIR filtering, (b) promoting sparsity in a selected dictionary through iterative thresholding, and (c) extracting high frequency information from the approximation to refine the initial estimate. For the sparse modeling, a shearlet dictionary is chosen to yield a multiscale directional representation. The proposed algorithm is compared to several state-of-the-art methods to assess its objective as well as subjective performance. Compared to the cubic spline interpolation method, an average PSNR gain of around 0.8 dB is observed over a dataset of 200 images

Impact of laminar flow velocity of different acids on enamel calcium loss

Objective: The aim of the study was to evaluate the impact of flow velocity under laminar flow conditions of different acidic solutions on enamel erosion. Material and methods: A total of 240 bovine enamel specimens were prepared and allocated to 30 groups (n = 8 each). Samples of 18 groups were superfused in a flow chamber system with laminar flow behavior using 1ml of citric acid or hydrochloric acid (HCl) of pH 2.0, 2.6 or 3.0. Flow rates in the sample chamber were adjusted to 10, 60 or 100μl/min. To simulate turbulent flow behavior, samples of six groups were immersed in 1ml of the respective solution, which was vortexed (15min, 600rpm). For simulating non-agitated conditions, specimens of the remaining six groups were immersed in 1ml of the respective solution without stirring. Calcium in the solutions, released from the enamel samples, was determined using Arsenazo III method. Results: For acidic solutions of pH 2.6 and 3.0, erosive potential of citric acid was equivalent to that of HCl at a flow of 100μl/min. The same observation was made for the samples subjected to turbulent conditions at pH 3. At all other conditions, citric acid induced a significantly higher calcium loss than HCl. Conclusion: It is concluded that under slow laminar flow conditions, flow rate variations lead to higher erosive impact of citric acid compared to hydrochloric acid at pH 2.0, but not at pH ≥ 2.6 and increasing laminar flow or turbulent conditions. Clinical relevance: Erosive enamel dissolution under laminar flow conditions is a complex issue influenced by flow rate and acidic substrat

Effects of various fluoride solutions on enamel erosion in vitro

The objective of this in vitro study was to investigate the effect of different fluoride solutions on enamel erosion. Human enamel specimens were pretreated with 1 of 10 different fluoride solutions (n = 20): TiF(4), NaF, AmF, ZnF(2), or SnF(2), each at native pH (pH range: 1.2-7.8) or buffered pH (pH = 4). The control group samples received no fluoride pretreatment. All samples were then eroded by citric acid (pH 2.6) for 6 x 1 min daily over 5 days. Between the erosive cycles, the samples were stored in artificial saliva. Erosion effects were investigated by surface profilometry (n = 10), scanning electron microscopy (n = 4), and energy-dispersive X-ray spectroscopy (n = 6) after fluoride pretreatment and after erosion. To test the effects of pH only, additional experiments were carried out with fluoride-free solutions at similar pH to that of fluoride solutions. In general, AmF solution was more effective in protecting enamel erosion compared to all other fluoride agents. However, the application of native TiF(4), native and buffered SnF(2), and native and buffered AmF solutions also resulted in significantly less enamel loss compared to the control group. A Ti-rich coating was formed after application of native TiF(4), but partially dissolved due to erosive attack. Samples pretreated with SnF(2) showed a significant increase in surface tin content. Surface fluoride concentration was significantly increased by native TiF(4), native and buffered AmF, buffered ZnF(2), and buffered NaF application. Under the current experimental setting, the fluoride agents at lower pH had better protective potential. Highly concentrated TiF(4), AmF, and SnF(2) solution was effective in inhibiting erosion of enamel

Electroencephalography in delirium assessment: a scoping review

Background Delirium is a common disorder affecting around 31% of patients in the intensive care unit (ICU). Delirium assessment scores such as the Confusion Assessment Method (CAM) are time-consuming, they cannot differentiate between different types of delirium and their etiologies, and they may have low sensitivities in the clinical setting. While today, electroencephalography (EEG) is increasingly being applied to delirious patients in the ICU, a lack of clear cut EEG signs, leads to inconsistent assessments. Methods We therefore conducted a scoping review on EEG findings in delirium. One thousand two hundred thirty-six articles identified through database search on PubMed and Embase were reviewed. Finally, 33 original articles were included in the synthesis. Results EEG seems to offer manifold possibilities in diagnosing delirium. All 33 studies showed a certain degree of qualitative or quantitative EEG alterations in delirium. Thus, normal routine (rEEG) and continuous EEG (cEEG) make presence of delirium very unlikely. All 33 studies used different research protocols to at least some extent. These include differences in time points, duration, conditions, and recording methods of EEG, as well as different patient populations, and diagnostic methods for delirium. Thus, a quantitative synthesis and common recommendations are so far elusive. Conclusion Future studies should compare the different methods of EEG recording and evaluation to identify robust parameters for everyday use. Evidence for quantitative bi-electrode delirium detection based on increased relative delta power and decreased beta power is growing and should be further pursued. Additionally, EEG studies on the evolution of a delirium including patient outcomes are needed

In Search of a Meaningful Story: Oral History and Triathlon Memory in Australia

High Efficiency Video Coding (HEVC) is currently being prepared as the newest video coding standard of the ITU-T Video Coding Experts Group and the ISO/IEC Moving Picture Experts Group. The main goal of the HEVC standardization effort is to enable significantly improved compression performance relative to existing standards-in the range of 50% bit-rate reduction for equal perceptual video quality. This paper provides an overview of the technical features and characteristics of the HEVC standard

Pacemaker implantation in small hospitals: complication rates comparable to larger centres

Some countries have a demography that makes it necessary to maintain relatively small pacemaker centres. We wanted to assess the quality of pacemaker surgery in two such hospitals. Through patient records we gathered information on ∼535 consecutive primary pacemaker implantations in two small pacemaker centres with 30 and 80 annual operations, respectively. All patients were followed for 3 years. All complications documented in the patient records were registered. Furthermore, we performed a non-systematic literature search comparing our data with reports from major centres published over the last 10 years.We found 72 complications in 64 (12.0%) of the patients, the most common being bleeding, lead failure, and pneumothorax. If minor bleedings without any consequences for the patients are excluded, the number of complications was 46 in 40 patients (7.5%). We had to reoperate on 5.2% of the patients. There was no statistically significant difference in complication rates between the two hospitals. Education candidates generated statistically significant more complications than experienced doctors (13.7 vs. 7.1%, P < 0.05). There are no generally accepted norms of complication rates in pacemaker surgery. However, we found no indications that our centres have a rate of complications that is unacceptably high