An Efficient Concealment Algorithm for Inter Frames Based on Block-Level and Pixel-Level Motion Vector Extrapolation

2014 ◽  
Vol 635-637 ◽  
pp. 1026-1029
Author(s):  
Geng Wei ◽  
Ruo Ying Wang ◽  
Yu Dong Zhang
Keyword(s):  
Motion Vector ◽  
Vector Extrapolation ◽  
Different Types ◽  
Highly Effective ◽  
Block Level ◽  
Simulation Results ◽  
Channel Errors

In this paper, a frame concealment scheme is proposed to combat the channel errors by using block-level and pixel-level motion vector extrapolation (MVE). Firstly, the proposed algorithm classifys the lost blocks into different types and then determines their corresponding MVs. Secondly, by using the pixel-level MV extrapolation, the candidate MV set of different lost pixels is obtained combined with the MVs of the blocks. Simulation results show this method is highly effective in sense of PSNR.

An Improved Error Concealment Based on Redundant Motion Vector Information

2012 ◽  
Vol 532-533 ◽  
pp. 1219-1224
Author(s):  
Hong Tao Deng
Keyword(s):  
Video Transmission ◽  
Error Concealment ◽  
Video Quality ◽  
Motion Vector ◽  
Compressed Video ◽  
Vector Information ◽  
Vector Estimation ◽  
Channel Errors ◽  
Bit Stream

During video transmission over error prone network, compressed video bit-stream is sensitive to channel errors that may degrade the decoded pictures severely. In order to solve this problem, error concealment technique is a useful post-processing tool for recovering the lost information. In these methods, how to estimate the lost motion vector correctly is important for the quality of decoded picture. In order to recover the lost motion vector, an Decoder Motion Vector Estimation (DMVE) criterion was proposed and have well effect for recover the lost blocks. In this paper, we propose an improved error concealment method based on DMVE, which exploits the accurate motion vector by using redundant motion vector information. The experimental results with an H.264 codec show that our method improves both subjective and objective decoder reconstructed video quality, especially for sequences of drastic motion.

Hypernetwork models based on random hypergraphs

2019 ◽  
Vol 30 (08) ◽  
pp. 1950052
Author(s):  
Feng Hu ◽  
Jin-Li Guo ◽  
Fa-Xu Li ◽  
Hai-Xing Zhao
Keyword(s):  
Field Theory ◽  
Mean Field Theory ◽  
Mean Field ◽  
World Systems ◽  
Uniform Hypergraphs ◽  
Different Types ◽  
Powerful Means ◽  
Simulation Results ◽  
Parameter Values ◽  
Random Hypergraphs

Hypernetworks are ubiquitous in real-world systems. They provide a powerful means of accurately depicting networks of different types of entity and will attract more attention from researchers in the future. Most previous hypernetwork research has been focused on the application and modeling of uniform hypernetworks, which are based on uniform hypergraphs. However, random hypernetworks are generally more common, therefore, it is useful to investigate the evolution mechanisms of random hypernetworks. In this paper, we construct three dynamic evolutional models of hypernetworks, namely the equal-probability random hypernetwork model, the Poisson-probability random hypernetwork model and the certain-probability random hypernetwork model. Furthermore, we analyze the hyperdegree distributions of the three models with mean-field theory, and we simulate each model numerically with different parameter values. The simulation results agree well with the results of our theoretical analysis, and the findings indicate that our models could help understand the structure and evolution mechanisms of real systems.

FOCUSING CONTROL BASED ON SPPs-SCATTERING MODULATION

2010 ◽  
Vol 19 (04) ◽  
pp. 535-541 ◽  
Author(s):  
FENGHUAN HAO ◽  
RUI WANG ◽  
JIA WANG
Keyword(s):  
Metal Film ◽  
Design Method ◽  
Control Device ◽  
Constructive Interference ◽  
Propagation Length ◽  
Exit Surface ◽  
Different Types ◽  
Focus Spot ◽  
Simulation Results

We demonstrate a design method of focusing-control device, which consists of single metallic nano-slit surrounded with the grooves at the metal exit surface. According to the principle of the constructive interference, the grooves are positioned to scatter the SPPs to the radiation lights with desired phases. The role of SPPs in the focusing control is investigated, by applying the design method in the four different types of metal film. The simulation results indicate that the focusing effects are dependant on the types of metal film, the metal film which supports the SPPs with a long propagation length can form an apparent focus spot, and the reason is discussed.

Thermomechanical Analysis of Poly (Bisphenol-A Carbonate) Performance and Molecular Simulation

2013 ◽  
Vol 781-784 ◽  
pp. 576-579
Author(s):  
Xiu Juan Wang ◽  
Xiu Ting Zheng ◽  
Meng Song ◽  
Xiu Ying Zhao ◽  
Si Zhu Wu
Keyword(s):  
Molecular Structure ◽  
Mechanical Properties ◽  
Thermal Stability ◽  
Bisphenol A ◽  
Molecular Simulation ◽  
Simulation Method ◽  
Thermomechanical Analysis ◽  
Optical Performance ◽  
Different Types ◽  
Simulation Results

This work studied the influence of different molecular structure of polycarbonate on its properties. Different types of polycarbonate molecular chain models were built by molecular simulation method. By combining experimental and molecular dynamic simulation results, it is concluded that the polycarbonate-OQ2720 has better thermal stability, mechanical properties and optical performance, which is a better choice for aviation materials and manufacturing process.

A Unified Analytical Framework for Ship Domains

2009 ◽  
Vol 62 (4) ◽  
pp. 643-655 ◽  
Author(s):  
Ning Wang ◽  
Xianyao Meng ◽  
Qingyang Xu ◽  
Zuwen Wang
Keyword(s):  
Collision Avoidance ◽  
Traffic Engineering ◽  
Analytical Framework ◽  
Domain Model ◽  
Analytical Models ◽  
Collision Risk ◽  
Marine Traffic ◽  
Different Types ◽  
Domain Models ◽  
Simulation Results

Most of the existing typical ship domains have been comprehensively reviewed and classified. Most of these ship domains are described in a geometrical manner that is difficult to apply to practices and simulations in marine traffic engineering. According to different types of geometrical ship domains, we have proposed mathematical models, based on which a unified analytical framework has been established. It is feasible and practical for the analytical models to be applied to the assessment of navigational safety, collision avoidance and trajectory planning, etc. Finally, some computer simulations and comparative studies of the proposed domain model have been presented and the simulation results show that the uniform analytical framework for ship domains is effective and identical to the original geometrical ones. It should be noted that the analytical domain models could be directly applied in any collision risk, collision avoidance or VTS system while the geometrical ones would be more illustrative but less practical or analytical.

scholarly journals Research on Influence of Different types of Orifice on Axial Steady-state Flow Force in Cartridge Proportional Valve

2019 ◽  
Author(s):  
Li Tan ◽  
Haibo Xie ◽  
Jianbin Liu ◽  
Hanben Chen ◽  
Huayong Yang
Keyword(s):  
Steady State ◽  
Test Bench ◽  
Research Model ◽  
Steady State Flow ◽  
Cfd Simulations ◽  
Proportional Valve ◽  
State Flow ◽  
Different Types ◽  
Negative Effect ◽  
Simulation Results

This article mainly investigates how orifice structure influences the characteristics of steady-state flow force. The research model of this paper is originated from a cartridge proportional valve. Firstly, predicting characteristics of the flow force working on poppet in different types of orifice through CFD simulations; secondly, several parameters of poppet and seat, which may affect the characteristics of flow force, are defined, a series of CFD calculations were conducted to find a rule how each parameter influences flow force; thirdly, according to the analysis, optimization of orifice structure parameters has been successfully realized. Finally, a test bench was established to validate the simulation results. The results show that the orifice type has a significant influence on flow force, which indicates that choosing certain type of orifice can effectively decrease the influence of flow force, and the negative effect of flow force can be reduced within an acceptable extent. Besides, the influence of orifice on pressure difference has been also taken into account. The experimental results agree well with the simulative one.

scholarly journals Modelling the High Mercury Wet deposition in the Southeastern US by WRF-GC

2022 ◽  
Author(s):  
Xiaotian Xu ◽  
Xu Feng ◽  
Haipeng Lin ◽  
Peng Zhang ◽  
Shaojian Huang ◽  
...  
Keyword(s):  
United States ◽  
Wet Deposition ◽  
Deep Convection ◽  
Southeastern United States ◽  
Convective Precipitation ◽  
Mercury Deposition ◽  
Southeastern Us ◽  
Different Types ◽  
High Mercury ◽  
Simulation Results

Abstract. High mercury wet deposition in southeastern United States has been noticed for many years. Previous studies came up with a theory that it was associated with high-altitude divalent mercury scavenged by convective precipitation. Given the coarse resolution of previous models (e.g. GEOS-Chem), this theory is still not fully tested. Here we employed a newly developed WRF-GEOS-Chem (WRF-GC) model implemented with mercury simulation. We conduct extensive model benchmarking by comparing WRF-GC with different resolutions (from 50 km to 25 km) to GEOS-Chem output (4° × 5°) and data from Mercury Deposition Network (MDN) in July–September 2013. The comparison of mercury wet deposition from two models both present high mercury wet deposition in southeastern United States. We divided simulation results by heights, different types of precipitation and combination of these two variations together and find most of mercury wet deposition concentrates on higher space and caused by convective precipitation. Therefore, we conclude that it is the deep convection caused enhanced mercury wet deposition in the southeastern United States.

scholarly journals Multivariate Geostatistical Modeling and Risk Analysis of Beach Litter: A Case Study of Playa Blanca Beach, Chile

2020 ◽  
Vol 17 (22) ◽  
pp. 8384
Author(s):  
Mohammad Maleki ◽  
Kevin Soria
Keyword(s):  
Spatial Distribution ◽  
Geostatistical Simulation ◽  
Geostatistical Modeling ◽  
Negative Effects ◽  
Cigarette Butts ◽  
Risk Of Injury ◽  
Different Types ◽  
Beach Litter ◽  
Simulation Results

Beach litter is a worldwide problem that has several negative effects. A first step in preventing an environmental hazard is to determine and model the level of contamination. In this paper, geostatistical simulation is used to model two main forms of beach litter (cigarette butts and sharp items) in one of the most contaminated beaches in Antofagasta, Chile. A hundred realizations of cigarette butts and broken glass are generated to emulate their joint spatial distribution. The simulation results are used to classify the beach into different areas with respect to the risk of injury by broken glass and the level of contamination by cigarette butts. The models obtained can be used by local authorities in beach clean-up programs and by visitors to beaches in choosing the safest and cleanest areas. The results demonstrate the capability of geostatistical simulation algorithms to model different types of beach litter.

scholarly journals The effect of impurity on miscible CO2 displacement mechanism

2019 ◽  
Vol 74 ◽  
pp. 86
Author(s):  
Erhui Luo ◽  
Yongle Hu ◽  
Jianjun Wang ◽  
Zifei Fan ◽  
Qingying Hou ◽  
...  
Keyword(s):  
Phase Behavior ◽  
Oil Recovery ◽  
Maximum Level ◽  
Volatile Oil ◽  
Real Field ◽  
Displacement Mechanism ◽  
Black Oil ◽  
Different Types ◽  
Reservoir Conditions ◽  
Simulation Results

The CO2 displacement is one of the gasflooding Enhanced Oil Recovery (EOR) methods. The application from volatile oil to black oil is popular mainly because CO2 requires a relatively low miscibility pressure, which is suitable to most reservoir conditions. However, CO2 always contains some impurity, such as CH4, H2S and N2, leading to the change of phase behavior and flooding efficiency. Whether the gasflooding achieves successfully miscible displacement depends on the reservoir pressure and temperature, injected solvent and crude oil compositions. So three different types of oil samples from the real field are selected and mixtures of CH4, H2S and N2 with various CO2 concentrations as the solvent are considered. After a series of experimental data are excellently matched, three nine-pseudocomponent models are generated based on the thermodynamic Equation-of-State (EoS), which are capable of accurately predicting the complicated phase behavior. Three common tools of pressure–temperature (P–T), pressure–composition (P–X) and pseudoternary diagrams are used to display and analyze the alteration of phase behavior and types of displacement mechanism. Simulation results show that H2S is favorable to attain miscibility while CH4 and N2 are adverse, and the former can reduce the Multiple Contact Miscibility (MCM) pressure by the maximum level of 1.675 MPa per 0.1 mol. In addition, the phase envelope of the mixtures CO2/H2S displacing the reservoir oil on the pseudoternary diagram behaves a triangle shape, indicating the condensing-dominated process. While most phase envelopes of CO2/CH4 and CO2/N2 exhibit the trump and bell shapes, revealing the MCM of vaporization.

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