Impact of scalability in video transmission in promotion-capable differentiated services networks

Transmission of high quality video over the Internet faces many challenges including unpredictable packet loss characteristics of the current Internet and the heterogeneity of receivers in terms of their bandwidth and processing capabilities. To address these challanges, we propose an architecture in this paper that is based on the temporally scalable and error resilient video coding mode of the H.263+ codec. In this architecture, the video frames will be transported over a new generation IP network that supports differentiated services (Diffserv). We also propose a novel Two Rate Three Color Promotion-Capable Marker (trTCPCM) to be used at the edge of the diffserv network. Our simulation study demonstrates that an average of 30 dB can be achieved in case of highly congested links

Rate-distortion optimization for stereoscopic video streaming with unequal error protection

We consider an error-resilient stereoscopic streaming system that uses an H.264-based multiview video codec and a rateless Raptor code for recovery from packet losses. One aim of the present work is to suggest a heuristic methodology for modeling the end-to-end rate-distortion (RD) characteristic of such a system. Another aim is to show how to make use of such a model to optimally select the parameters of the video codec and the Raptor code to minimize the overall distortion. Specifically, the proposed system models the RD curve of video encoder and performance of channel codec to jointly derive the optimal encoder bit rates and unequal error protection (UEP) rates specific to the layered stereoscopic video streaming. We define analytical RD curve modeling for each layer that includes the interdependency of these layers. A heuristic analytical model of the performance of Raptor codes is also defined. Furthermore, the distortion on the stereoscopic video quality caused by packet losses is estimated. Finally, analytical models and estimated single-packet loss distortions are used to minimize the end-to-end distortion and to obtain optimal encoder bit rates and UEP rates. The simulation results clearly demonstrate the significant quality gain against the nonoptimized schemes

Super-resolution using multiple quantized images

In this paper, we study the effect of limited amplitude resolution (pixel depth) in super-resolution problem. The problem we address differs from the standard super-resolution problem in that amplitude resolution is considered as important as spatial resolution. We study the trade-off between the pixel depth and spatial resolution of low resolution (LR) images in order to obtain the best visual quality in the reconstructed high resolution (HR) image. The proposed framework reveals great flexibility in terms of pixel depth and number of LR images in super-resolution problem, and demonstrates that it is possible to obtain target visual qualities with different measurement scenarios including images with different amplitude and spatial resolutions. © 2010 IEEE

Error resilient layered stereoscopic video streaming

In this paper, error resilient stereoscopic video streaming problem is addressed. Two different Forward Error Correction (FEC) codes namely Systematic LT and RS codes are utilized to protect the stereoscopic video data against transmission errors. Initially, the stereoscopic video is categorized in 3 layers with different priorities. Then, a packetization scheme is used to increase the efficiency of error protection. A comparative analysis of RS and LT codes are provided via simulations to observe the optimum packetization and UEP strategies

Rate-distortion optimized layered stereoscopic video streaming with raptor codes

A near optimal streaming system for stereoscopic video is proposed. Initially, the stereoscopic video is separated into three layers and the approximate analytical model of the Rate-Distortion (RD) curve of each layer is calculated from sufficient number of rate and distortion samples. The analytical modeling includes the interdependency of the defined layers. Then, the analytical models are used to derive the optimal source encoding rates for a given channel bandwidth. The distortion in the quality of the stereoscopic video that is caused by losing a NAL unit from the defined layers is estimated to minimize the average distortion of a single NAL unit loss. The minimization is performed over protection rates allocated to each layer. Raptor codes are utilized as the error protection scheme due to their novelty and suitability in video transmission. The layers are protected unequally using Raptor codes according to the parity ratios allocated to the layers. Comparison of the defined scheme with two other protection allocation schemes is provided via simulations to observe the quality of stereoscopic video. ©2007 IEEE

Reporting guidelines for surgical technique could be improved: a scoping review and a call for action.

To identify reporting guidelines related to surgical technique and propose recommendations for areas that require improvement. A protocol-guided scoping review was conducted. A literature search of MEDLINE, the EQUATOR Network Library, Google Scholar, and Networked Digital Library of Theses and Dissertations was conducted to identify surgical technique reporting guidelines published up to December 31, 2021. We finally included 55 surgical technique reporting guidelines, vascular surgery (n = 18, 32.7%) was the most common among the clinical specialties covered. The included guidelines generally showed a low degree of international and multidisciplinary cooperation. Few guidelines provided a detailed development process (n = 14, 25.5%), conducted a systematic literature review (n = 13, 23.6%), used the Delphi method (n = 4, 7.3%), or described post-publication strategy (n = 6, 10.9%). The vast majority guidelines focused on the reporting of intraoperative period (n = 50, 90.9%). However, of the guidelines requiring detailed descriptions of surgical technique methodology (n = 43, 78.2%), most failed to provide guidance on what constitutes an adequate description. Our study demonstrates significant deficiencies in the development methodology and practicality of reporting guidelines for surgical technique. A standardized reporting guideline that is developed rigorously and focuses on details of surgical technique may serve as a necessary impetus for change

Study of CP violation in Dalitz-plot analyses of B0 --> K+K-KS, B+ --> K+K-K+, and B+ --> KSKSK+

We perform amplitude analyses of the decays $B^0 \to K^+K^-K^0_S$, $B^+ \rightarrow K^+K^-K^+$, and $B^+ \to K^0_S K^0_S K^+$, and measure CP-violating parameters and partial branching fractions. The results are based on a data sample of approximately $470\times 10^6$ $B\bar{B}$ decays, collected with the BABAR detector at the PEP-II asymmetric-energy $B$ factory at the SLAC National Accelerator Laboratory. For $B^+ \to K^+K^-K^+$, we find a direct CP asymmetry in $B^+ \to \phi(1020)K^+$ of $A_{CP}= (12.8\pm 4.4 \pm 1.3)$, which differs from zero by $2.8 \sigma$. For $B^0 \to K^+K^-K^0_S$, we measure the CP-violating phase $\beta_{\rm eff} (\phi(1020)K^0_S) = (21\pm 6 \pm 2)^\circ$. For $B^+ \to K^0_S K^0_S K^+$, we measure an overall direct CP asymmetry of $A_{CP} = (4 ^{+4}_{-5} \pm 2)$. We also perform an angular-moment analysis of the three channels, and determine that the $f_X(1500)$ state can be described well by the sum of the resonances $f_0(1500)$, $f_2^{\prime}(1525)$, and $f_0(1710)$.Comment: 35 pages, 68 postscript figures. v3 - minor modifications to agree with published versio

Optimal streaming under rate constraints (Ïngilizce) [Bant genişliǧi kisiti altinda videonun en i̇yi i̇letimi (Türkçe)]

In this paper, we propose an optimal video streaming framework using retransmissions based on the theory of Markov Decision Processes (MDP). Using MDPs, we calculate average reward optimal policies so as to maximize the on time delivery probability of video frames in the transmission window while conforming to network-imposed available bandwidth constraints. The effectiveness of the proposed approach is validated by comparing the results with theoretically obtained rate-distortion curves corresponding to the optimal policies by using the distortion model in [2] © 2006 IEEE

Çok-akişli eşler arasi i̇steǧe baǧli video sistemlerinin Markov zinciri tabanli güvenilirlik modellemesi

[No abstract available