No reference objective quality metric for stereoscopic 3D video

The stereoscopic three-dimensional (3D) video technologies have achieved significant success in providing enhanced immersive experience to consumers. However network delivery of 3D video content at good quality levels is challenging mostly due to the variable network conditions. In this context, efficient objective 3D video quality assessment is a critical aspect, in particular for video service providers who need to adjust the video delivery process to the network conditions in real-time. Current objective 3D video quality assessment methods are reference-based, requiring the availability of the original 3D video sequences, which is difficult to achieve in practice. Additionally, most of the existing 3D video quality metrics are developed for depth-enhanced 3D. This paper proposes the No reference objective Video Quality Metric (NVQM) for real-time 3D video quality assessment. NVQM considers the correlation between network packet loss and perceptual video quality for different bit-rate video sequences. NVQM is modeled based on the video quality model specified in ITU-T G.1070 and tuned according to results of extensive subjective tests. NVQM was developed for the evaluation of side-by-side stereoscopic 3D sequences, the most widely commercialized 3D video format. The performance of NVQM is studied by comparing against three state-of-the-art video quality objective models: structural similarity index (SSIM), video quality metric (VQM), and ITU-T G.1070. Results show that NVQM outperforms the existing objective metrics with up to 23% in terms of accuracy

Balancing energy and quality-awareness:a MAC-Llayer duty-cycle management solution for multimedia delivery over wireless mesh networks

Energy consumption has been a critical factor for mobile video applications. The quality of content delivery over wireless mesh networks consist of such devices is also considered important. Existing energy-aware research and industrial efforts focus on reducing high energy-consuming working periods of mesh devices, at the expense of decreasing the quality of video content. This article proposes an energy-quality-balanced solution AOC-MAC deployed at the MAC layer, working in conjunction with an energy-aware routing algorithm for wireless mesh devices. The simulation and perceptual test results are also presented in order to investigate the performance of the proposed solution. In particular, the impacts of content delivery data rate, mesh network topology scale and mesh device mobility are studied. Results demonstrate that AOC-MAC obtains up to 23% energy savings at roughly the same content delivery quality level, in comparison with the IEEE 802.11s MAC protocol

Improving the GeAsSe Ovonic Threshold Switching Characteristics by Carbon Buffer Layers for Ultralow Leakage Current (∼0.4 nA) and Low Drift Characteristics

Volatile Ovonic threshold switching (OTS) selectors have been regarded as the critical component of highly integrated three-dimensional (3D) cross-point array nonvolatile memory systems. However, relatively high leakage current hinders the further reduction of power consumption in the crossbar array. In addition, the threshold voltage drift phenomenon hinders the improvement of device reliability. Utilizing the buffer layer can effectively reduce the interaction between electrodes and the active layer in the cross-point architecture. Here, it manifests that leakage current can be reduced to ∼0.4 nA with a 5 nm thick amorphous carbon layer as a buffer layer in the GeAsSe-based OTS device, where the carbon layer stabilizes the composition of GeAsSe during the electrical switching cycles. It is also found that the carbon layer leads to a lower threshold voltage drift (35.6 mv/dec) and excellent endurance (>109 cycles with ∼0.4 nA ON-state current). The conduction mechanism analysis demonstrates that the inhibition of the carbon layer on drift originates from the high barrier height from delocalized states transformed into localized states. This work clearly demonstrates the role of the carbon layer and facilitates future 3D crossbar-storage technology applications