GOP Adaptation Coding of H.264/SVC Based on Precise Positions of Video Cuts

( Yunpeng Liu ),( Renfang Wang ),( Huixia Xu ),( Dechao Sun ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.7

Hierarchical B-frame coding was introduced into H.264/SVC to provide temporal scalability and improve coding performance. A content analysis-based adaptive group of picture structure (AGS) can further improve the coding efficiency, but damages the inter-frame correlation and temporal scalability of hierarchical B-frame to different degrees. In this paper, we propose a group of pictures (GOP) adaptation coding method based on the positions of video cuts. First, the cut positions are accurately detected by the combination of motion coherence (MC) and mutual information (MI); then the GOP is adaptively and proportionately set by the analysis of MC in one scene. In addition, we propose a binary tree algorithm to achieve the temporal scalability of any size of GOP. The results for test sequences and real videos show that the proposed method reduces the bit rate by up to about 15%, achieves a performance gain of about 0.28-1.67 dB over a fixed GOP, and has the advantages of better transmission resilience and video summaries.

Experimental Research on the Shear Performance of the Two-Storey Composite Cold-Formed Thin-Walled Steel Wall

Yunpeng Chu,Xiangrong He,Yong Yao,Hongjie Hou 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.2

The composite wall made of the cold-formed thin-walled steel has good shear performance. When it is used in buildings, its weak part is located at the joint of floors and becomes the first broken part under the action of the earthquake. The shear test of five Two-storey Composite Cold-formed Thin-walled Steel Walls (TCS) under cyclic loading has been carried out. The influences of axial pressures, types of anti-pulling bolts and panel materials on shear performances are examined. The results show that under the same working condition, the energy dissipation capacity of calcium silicate panel specimens is significantly lager than that of the gypsum panel specimens, and the ultimate bearing capacity is also greater. The axial pressure has a great influence on the ultimate bearing capacity and energy dissipation capacity of the specimens. Compared with the specimens designed according to the Ref. (JGJ227-2011, 2011), the energy dissipation capacity of all specimens is increased by 3.25 times. The extrusion between the self-tapping screw and the wall panel causes the screw to fall off, resulting in a sharp decrease in the rigidity of the specimens at the initial loading stage. After the failure of the wall panel, the bottom and top beam are restricted by double nuts of the anti-pulling bolt at the joint of floors, so the bearing capacity of specimens decreases slowly at the later loading stage. The tilt angle of anti-pulling bolt increases when the TCS wall is loaded to the later stage. The force state of the self-tapping screw on the hold-down is changed from bearing shear force to bearing tension and shear force, resulting in fast failure of the anti-pulling bolt suit. The load borne by the anti-pulling bolt suit is transferred to floor beams and their supporting stiffeners, causing them to collapse rapidly.

Echinacoside Ameliorates Cyclophosphamide-Induced Bladder Damage in Mice

Yunpeng Shao,Yu Liu,Baixin Shen,Qiao Zhou,Zhongqing Wei 한국식품영양과학회 2022 Journal of medicinal food Vol.25 No.7

Interstitial cystitis (IC) is featured by apoptosis and chronic inflammation in bladder tissue. We aimed to evaluate the effect of echinacoside (ECH), which is known to modulate inflammation and apoptosis on IC using relevant models. We established a mouse model of cystitis using cyclophosphamide (CYP) and treated human urothelium cells (SV-HUC-1) with lipopolysaccharide (LPS) + ATP as in vitro model. The bladder function was tested by urodynamics. Apoptosis of bladder cells was assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. Expressions of apoptosis-associated and inflammation-related proteins were assessed using western blotting. Treatment with ECH significantly improved bladder function, reduced inflammatory damage, and decreased apoptosis in the models. Furthermore, ECH decreased the phosphorylation levels of IκB and NF-κB(p65), and upregulated the expression of peroxisome proliferator-activated receptor gamma (PPARγ), which are related to apoptosis and inflammation in CYP-induced mouse cystitis. Moreover, ECH did not reduce apoptosis of urothelial cells after treatment with PPARγ antagonist GW9662. Our findings suggest that ECH might have protective effect against IC in bladder and be mediated through modulation of the PPARγ/NF-κB pathway.

Numerical Analysis of Directional Rock Blasting with Continuous-Discontinuous Element Method

Yunpeng Li,Chun Feng,Yiming Zhang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.8

When simulating the directional blasting process, many researchers focus on the cutting and splitting effects who might pay more attention on the crushing effects when studying conventionalcut blasting. In this case, a numerical tool capable of capturing the strong discontinuity processes of quasi-brittle materials is highly preferable, where many blasting parameters should be calibrated and inputted. In this work, a hybrid finite-discrete elements method with explicit iterative procedure named Continuous-Discontinuous Elements Method (CDEM) is adopted to study the directional rock blasting processes. Landau model is used to capture the detonation effects, where the parameters are calibrated by comparing to the results provided by published literatures. We found that: i) The crack propagation mode of directional rock blasting is similar to those found in Brazilian splitting tests where the crack initiates from the midpoint of the connecting line of blast holes; ii) Compared with traditional cut blasting, the free surface has no significant influence on the blasting effect of directional cut blasting, while the spacing of the hole has great influence on the cutting effect. The index of fracture degree can be used to evaluate the blasting effect quantitatively. This work partly reveals some cracking patterns and rules of directional rock blasting, which may assist the engineers to develop improved precise blasting technologies.

Finite-time Issue of Discrete-time Linear Switched Systems With Partial Finite-time Unstable Modes Based on an Inverse Weighted Switching Scheme

Yunpeng Zhan,Ruihua Wang,Shumin Fei 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.2

The work proposes a multiple convex Lyapunov function and an inverse weighted switching scheme to investigate the finite-time stability and finite-time boundedness for a class of discrete-time switched linear systems with partial finite-time unstable modes. A multiple convex Lyapunov function is put forth by constructing a convex combination of positive definite matrices, which can relax the restricted conditions of the Lyapunov function and make it carry more decision variables than traditional Lyapunov function methods. Besides, the inverse weighted switching scheme is devised by summing the reciprocal of each dwell time with weighting coefficients, by which tighter dwell time bounds are ensured. On the basis of the new Lyapunov function and switching scheme, the finitetime control for a class of switched linear systems with partial finite-time unstable modes is addressed. Different from other researches that require all subsystems to be controllable, we only require the existence of one controllable subsystem. In the end, two numerical examples and a tunnel diode circuit example are provided to verify the effectiveness of the developed results.

Using Nano-powders to Improve the Interfacial Bonding Strength of Carbon Fiber/Epoxy Composites

Yunpeng Jiang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.5

The interfacial bonding strength is undoubtedly very crucial to the mechanical performance of carbon fiber/epoxycomposites. In this work, their bonding strength was studied by the experiments using single-lap joint specimens, which arebonded with the hybrid adhesive of epoxy resin mixing with different nano-powders of GNPs, nano-SiO2 and SiC whiskers. Adding such nano-powders effectively increases the interfacial bonding strength to different extent, and the inherentstrengthening mechanism was carefully analyzed based on the SEM observations of fractured surfaces. The bonding strengthwas difficult to avoid of the influence of the bending moment produced by the asymmetric geometry and off-centering tensileload, and thereby finite element modeling (FEM) was carried on to reveal this effect. This work would guide the processingto improve the interfacial bonding strength of carbon fiber/epoxy composites.

Machining scheme of aviation bearing bracket based on additive and subtractive hybrid manufacturing

Yunpeng Xie,Jianbin Tong,Yuqiang Fu,Zhongqi Sheng 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.9

Aviation bearing bracket is an important part of aircraft and other aviation products. In this paper, based on additive and subtractive hybrid manufacturing technology with high manufacturing flexibility and high machining accuracy, a machining scheme of aviation bearing bracket is designed. First, milling simulation was carried out to obtain the influence law of different cutting parameters on machining deformation, so as to guide the selection of reasonable finish machining parameters in the subsequent process planning. Then, the temperature field distribution of workpiece in the additive manufacturing was simulated, and the influence of different additive manufacturing parameters on the results was analyzed to determine the parameter selection range. Finally, considering the material utilization rate, machining accuracy, machining efficiency and machinability in the machining process of aviation bearing bracket, and proceeding from additive, subtractive and alternating manufacturing methods, the manufacturing process arrangement and process planning for aviation bearing bracket were designed.

Interference Alignment with Multiple Antennas for Single Group D2D Communications

Yunpeng Li,Kyunghi Chang 한국통신학회 2015 한국통신학회 학술대회논문집 Vol.2015 No.1

Variable speed sliding mode control of magnetic suspension linear synchronous motor based on feedback linearization

Yunpeng Sun,Yipeng Lan,Xiaolei Shi,Zelai Xu,Cheng Lei 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.11

In the high-speed and high-precision magnetic suspension linear synchronous motor, the non-linear coupling between armature current, suspension height and horizontal velocity, as well as the uncertain factors such as load disturbance, which will have many adverse effects on the control system. To solve these problems, this paper uses a feedbacklinearized control method. Through coordinate transformation and state feedback, the nonlinear model of motor affine is decoupled and linearized into three independent linear subsystems of straight axis current subsystem, horizontal speed subsystem and suspension height subsystem. In order to reduce the dependence of feedback linearization control on linear motor mathematical model and improve the robustness of servo system, so as to realize decoupling control of magnetic suspension linear synchronous motor, a variable speed reaching law sliding mode controller is designed on the basis of linearization model. Simulation and experimental results show that the dynamic and static performance of the system is enhanced significantly by using the proposed control strategy.

Opportunistic Wireless Internet Access in Vehicular Environments Using Enhanced WAVE Devices

Yunpeng Zang,Erik Weiss,Lothar Stibor,Bernhard Walke,Hui Chen,Xi Cheng 보안공학연구지원센터 2008 International Journal of Hybrid Information Techno Vol.1 No.2

The emerging Car-to-Car communication (C2C) technology, known as Wireless Access in Vehicular Environments (WAVE), enables vehicles on the roadway to communicate with each other and with the roadside infrastructure. In addition to safety-relevant services, drivers may also need Internet access through C2C communications for infotainment services and car maintenance services, as specified in MobilitY and CollAboRative Work in European Vehicle Emergency NeTworks (MYCAREVENT) project. In this article we propose solutions for providing on-board Internet access service to automotive users through C2C communications. The proposed solutions make use of roadside infrastructure and the novel MYCAREVENT Vehicular Communication Gateway (VCG) device. A management scheme is developed for the opportunistic wireless links between On-Board Units (OBUs) and Road-Side Units (RSUs), as well as between OBUs and VCGs in vehicular communications. Furthermore, we invent a novel MAC queue architecture addressing the drawback of the current WAVE MAC protocol in supporting unicast traffic in highly dynamic vehicular environments. At the end, stochastic simulation results are presented to prove the concepts and validate the proposed solutions.