551 research outputs found
PEA265: Perceptual Assessment of Video Compression Artifacts
The most widely used video encoders share a common hybrid coding framework
that includes block-based motion estimation/compensation and block-based
transform coding. Despite their high coding efficiency, the encoded videos
often exhibit visually annoying artifacts, denoted as Perceivable Encoding
Artifacts (PEAs), which significantly degrade the visual Qualityof- Experience
(QoE) of end users. To monitor and improve visual QoE, it is crucial to develop
subjective and objective measures that can identify and quantify various types
of PEAs. In this work, we make the first attempt to build a large-scale
subjectlabelled database composed of H.265/HEVC compressed videos containing
various PEAs. The database, namely the PEA265 database, includes 4 types of
spatial PEAs (i.e. blurring, blocking, ringing and color bleeding) and 2 types
of temporal PEAs (i.e. flickering and floating). Each containing at least
60,000 image or video patches with positive and negative labels. To objectively
identify these PEAs, we train Convolutional Neural Networks (CNNs) using the
PEA265 database. It appears that state-of-theart ResNeXt is capable of
identifying each type of PEAs with high accuracy. Furthermore, we define PEA
pattern and PEA intensity measures to quantify PEA levels of compressed video
sequence. We believe that the PEA265 database and our findings will benefit the
future development of video quality assessment methods and perceptually
motivated video encoders.Comment: 10 pages,15 figures,4 table
Status and strategies analysis on international standardization of auricular acupuncture points
AbstractObjectiveTo supply literature for developing an international standard of auricular acupuncture points.MethodsElectronic database searches were conducted in the Chinese National Knowledge Infrastructure and VIP, and the Western databases, Pubmed, the National Science and Technology Library, and the German Journal of Acupuncture, from 1990 to April, 2012. We also searched the documents of international symposiums for auricular acupuncture points (AAPs). Keywords were “auricular points”, “auricular acupuncture points”, “ear points”, or “auriculotherapy”.ResultsBasic and clinical research on AAPs was performed in China, the United States, France, and Germany. Clinical AAP research was done in Italy, Austria, Switzerland, Spain, the UK, Holland, Japan, Russia, and Africa. However, AAP research was not communicated internationally. The World Federation of Acupuncture-Moxibustion Societies recommended international standard of auricular acupuncture points (ISAAPs). Standardized nomenclature and locations of AAPs would provide a solid basis to draft an international standard organization.ConclusionExperts need to find common points from different countries or regions, provide evidence of different ideas, and list the proposal as a recommendation for an international standard
A Barrier-Lyapunov Actor-Critic Reinforcement Learning Approach for Safe and Stable Control
Reinforcement learning (RL) has demonstrated impressive performance in
various areas such as video games and robotics. However, ensuring safety and
stability, which are two critical properties from a control perspective,
remains a significant challenge when using RL to control real-world systems. In
this paper, we first provide definitions of safety and stability for the RL
system, and then combine the control barrier function (CBF) and control
Lyapunov function (CLF) methods with the actor-critic method in RL to propose a
Barrier-Lyapunov Actor-Critic (BLAC) framework which helps maintain the
aforementioned safety and stability for the system. In this framework, CBF
constraints for safety and CLF constraint for stability are constructed based
on the data sampled from the replay buffer, and the augmented Lagrangian method
is used to update the parameters of the RL-based controller. Furthermore, an
additional backup controller is introduced in case the RL-based controller
cannot provide valid control signals when safety and stability constraints
cannot be satisfied simultaneously. Simulation results show that this framework
yields a controller that can help the system approach the desired state and
cause fewer violations of safety constraints compared to baseline algorithms.Comment: Preprint submitted to IEEE CDC 202
Status and strategies analysis on international standardization of auricular acupuncture points
AbstractObjectiveTo supply literature for developing an international standard of auricular acupuncture points.MethodsElectronic database searches were conducted in the Chinese National Knowledge Infrastructure and VIP, and the Western databases, Pubmed, the National Science and Technology Library, and the German Journal of Acupuncture, from 1990 to April, 2012. We also searched the documents of international symposiums for auricular acupuncture points (AAPs). Keywords were “auricular points”, “auricular acupuncture points”, “ear points”, or “auriculotherapy”.ResultsBasic and clinical research on AAPs was performed in China, the United States, France, and Germany. Clinical AAP research was done in Italy, Austria, Switzerland, Spain, the UK, Holland, Japan, Russia, and Africa. However, AAP research was not communicated internationally. The World Federation of Acupuncture-Moxibustion Societies recommended international standard of auricular acupuncture points (ISAAPs). Standardized nomenclature and locations of AAPs would provide a solid basis to draft an international standard organization.ConclusionExperts need to find common points from different countries or regions, provide evidence of different ideas, and list the proposal as a recommendation for an international standard
Symmetric Stationary Boundary Layer
Considering the boundary layer problem in the case of two-dimensional flow
past a wedge with the wedge angle , Oleinik and
Samokhin obtained the local well-posedness results for . In this
paper, we establish the existence and uniqueness of classical solutions to the
Prandtl systems for arbitrary , which solves the steady case in Open
problem 6 proposed by Oleinik and Samokhin. Our proof is based on the maximum
principle technique at the Crocco coordinates and the most important
observation that when the fluid approaches a sharp point, it seems the
self-similar solutions. Then we obtain the existence and uniqueness of the
solution with the help of the self-similar solutions by the Line Method.
Furthermore, we similarly establish the well-posedness results of
three-dimensional flow past a cone.Comment: 34 pages, 2 figure
Saliency-Aware Spatio-Temporal Artifact Detection for Compressed Video Quality Assessment
Compressed videos often exhibit visually annoying artifacts, known as
Perceivable Encoding Artifacts (PEAs), which dramatically degrade video visual
quality. Subjective and objective measures capable of identifying and
quantifying various types of PEAs are critical in improving visual quality. In
this paper, we investigate the influence of four spatial PEAs (i.e. blurring,
blocking, bleeding, and ringing) and two temporal PEAs (i.e. flickering and
floating) on video quality. For spatial artifacts, we propose a visual saliency
model with a low computational cost and higher consistency with human visual
perception. In terms of temporal artifacts, self-attention based TimeSFormer is
improved to detect temporal artifacts. Based on the six types of PEAs, a
quality metric called Saliency-Aware Spatio-Temporal Artifacts Measurement
(SSTAM) is proposed. Experimental results demonstrate that the proposed method
outperforms state-of-the-art metrics. We believe that SSTAM will be beneficial
for optimizing video coding techniques
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