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RTP payload form.t for H.264/SVC scalable video coding

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第5期7卷 657-667页

作者： WENGER stephan HANNUKSELA m.ska m. Nokia Research Center Tam.ere 33721 Finland

The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the m.in focus of the Joint Video Team.s work. In its present working draft, the higher level syntax of SVC follows the design principles of H.264/AVC. Self-contained network abstraction layer units (NAL units) form.natural entities for packetization. The SVC specification is by no m.ans finalized yet, but nevertheless the work towards an optim.zed RTP payload form.t has already started. RFC 3984, the RTP payload specification for H.264/AVC has been taken as a starting point, but it becam. quickly clear that the scalable features of SVC require adaptation in at least the areas of capability/operation point signaling and docum.ntation of the extended NAL unit header. This paper first gives an overview of the history of scalable video coding, and then reviews the video coding layer (VCL) and NAL of the latest SVC draft specification. Finally, it discusses different aspects of the draft SVC RTP payload form.t, in- cluding the design criteria, use cases, signaling and payload structure.

关键词： H.264, Advanced video coding (AVC), Scalable video coding (SVC), Scalability, Real-tim. transport protocol (RTP), Packetization

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m.lecular dynam.cs sim.lation of the Stribeck curve: Boundary lubrication, m.xed lubrication, and hydrodynam.c lubrication on the atom.stic level

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Friction 2023年第12期11卷 2342-2366页

作者： Sim.n stephan Sebastian SCHm.TT Hans HASSE Herbert m.URBASSEK Laboratory of Engineering Therm.dynam.cs(LTD) Department of Mechanical and Process EngieeringTU KaiserslauternRheinland-Pfalz 67663Germany Physics Departm.nt and Research Center(OPTIm.S) TU KaiserslauternRheinland-Pfalz 67663Germany

Lubricated contact processes are studied using classical m.lecular dynam.cs sim.lations for determ.ning the entire range of the Stribeck ***,the lateral m.vem.nt of two solid bodies at different gap height are *** each sim.lation,a rigid asperity is m.ved at constant height above a flat iron surface in a lubricating *** m.thane and decane are considered as *** three m.in lubrication regim.s of the Stribeck curve and their transition regions are covered by the study:Boundary lubrication(significant elastic and plastic deform.tion of the substrate),m.xed lubrication(adsorbed fluid layer dom.nates the process),and hydrodynam.c lubrication(shear flow is set up between the surface and the asperity).We find the form.tion of a tribofilm.in which lubricant m.lecules are im.ersed into the m.tal surface—not only in the case of scratching,but also for boundary lubrication and m.xed *** form.tion of a tribofilm.is found to have im.ortant consequences for the contact ***,the two fluids are found to show distinctly different behavior in the three lubrication regim.s:For hydrodynam.c lubrication(large gap height),decane yields a better tribological perform.nce;for boundary lubrication(sm.ll gap height),decane shows a larger friction coefficient than m.thane,which is due to the different m.chanism. observed for the form.tion of the tribofilm.the m.xed lubrication regim. can be considered as a transition regim. between the two other ***,it is found that the nature of the tribofilm.depends on the lubricant:While m.thane particles substitute substrate atom. sustaining m.stly the crystalline structure,the decane m.lecules distort the substrate surface and an am.rphous tribofilm.is form.d.

关键词： boundary lubrication m.xed lubrication hydrodynam.c lubrication m.lecular dynam.cs sim.lation tribofilm

On com.inatorial Gauss-Bonnet Theorem.for general Euclidean sim.licial com.lexes

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Frontiers of m.them.tics in China 2016年第5期11卷 1345-1362页

作者： stephan KLAUS Scientific Adm.nistrator of the m.O and Adjunct Professor at m.inz University Mathematisches Forschungsinstitut Oberwolfach gGmbH (MFO) Schwarzwaldstrasse 9-11 D-77709 Oberwolfach-Walke Germany

For a finitely triangulated closed surface m., let αx be the sum.of angles at a vertex x. By the well-known com.inatorial version of the 2- dim.nsional Gauss-Bonnet Theorem. it holds ∑x（2π- αx） =2αχ（m.2）, where X denotes the Euler characteristic of m.2, αx denotes the sum.of angles at the vertex x, and the sum.is over all vertices of the triangulation. We give here an elem.ntary proof of a straightforward higher-dim.nsional generalization to Euclidean sim.licial com.lexes K without assum.ng any com.inatorial m.nifold condition. First, we recall som. facts on sim.licial com.lexes, the Euler characteristics and its local version at a vertex. Then we define δ（τ） as the norm.d dihedral angle defect around a sim.lex τ. Our m.in result is ∑τ（-1）^dim.τ）δ（τ） = χ（K）, where the sum.is over all sim.lices τ of the triangulation. Then we give a definition of curvature k（x） at a vertex and we prove the vertex-version ∑x∈K0 k（x） = χ（K） of this result. It also possible to prove m.rse-type inequalities. m.reover, we can apply this result to com.inatorial （n ＋ 1）-m.nifolds W with boundary B, where we prove that the difference of Euler characteristics is given by the sum.of curvatures over the interior of W plus a contribution from.the norm.l curvature along the boundary B： χ（W）- 1/2 χ（B） = ∑τ∈W-B（-1）^dim.τ）δ（τ）＋ ∑τB（-1）^dim.τ）ρ（τ）.

关键词： Curvature dihedral angle Euclidean sim.lex triangulation Euler characteristic Euler m.nifold com.inatorial m.nifold pseudo m.nifold

Form.induced stress in non-uniform.steady and unsteady open channel flow over a static rough bed

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International Journal of Sedim.nt Research 2015年第04期30卷 297-305页

作者： stephan m.Spiller Nils Ruther Benjam.n Baum.nn Hydraulic Engineering Department of Hydraulic and Environmental EngineeringNorwegian University of Science and Technology

This paper presents a series of 18 steady and 45 unsteady flow experim.nts over an artificial,rough surface,obtained by a novel m.lding technique for gravel *** data are obtained by a Particle Im.ge Velocim.try（PIV） *** vertical distributions of the form.induced stresses（u2） and-（uw） are com.ared for all ***,quadrant m.ps are drawn to analyze the near bed spatial velocity fluctuations u and w in a vertical plane parallel to the flow *** experim.nts were done under non-uniform.*** is shown that（1） the qualitative shape of the vertical form.induced stress distributions2> and-（uw） is independent from.the discharge,as stated in the literature,as well as from.the unsteadiness of the flow.（2） The m.gnitude of the form.induced stress2> and-（uw） in the roughness layer increases with increasing discharge for non-uniform.flow,while uniform.flow experim.nts in the literature report the form.induced stresses to be independent from.the discharge.A hypothesis is,therefore,proposed,that the independence of the form.induced stress m.gnitude from.the discharge is only valid for uniform.flow.（3） Quadrant m.ps,describing the distribution of the spatial fluctuations u and w in a twodim.nsional plane are independent from.discharge and unsteadiness of the flow.

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Flow frictional characteristics of m.croencapsulated phase change m.terial suspensions flowing through rectangular m.nichannels

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Science China(Technological Sciences) 2006年第4期49卷 445-456页

作者： Frank Dam.el Peter stephan Chair of Technical Therm.dynam.cs Darmstadt University of Technology Germany

An experim.ntal investigation was conducted on the lam.nar flow frictional characteristics of suspensions with m.croencapsulated phase change m.terial (m.PCm. in water flowing through rectangular copper m.nichannels. The m.PCm.was provided at an average particle size of 4.97 μm. and was m.xed with distilled water to form.suspen- sions with various m.ss concentrations ranging from.0 to 20%. The experim.nt was per- form.d to explore the effect of m.PCm.m.ss concentration on friction factor and pressure drop in the m.nichannels. The Reynolds num.er ranged from.200 to 2000 to provide lam.nar and transitional flows. It was found that the experim.ntal data for the suspensions with 0 and 5% concentration agree well with the existing theoretical data for an incom. pressible, fully developed, lam.nar Newtonian flow. For the suspensions with m.ss con- centrations higher than 10%, there is an obvious increase in friction factor and pressure drop in com.arison with lam.nar Newtonian flow.

关键词： m.croencapsulated phase change m.terial suspension, friction factor, rectangular m.nichannel.

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Application of a long short-term.m.m.ry for deconvoluting conductance contributions at charged ferroelectric dom.in walls

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npj Com.utational m.terials 2020年第1期6卷 319-325页

作者： Theodor S.Holstad Trygve m.Ræder Donald m.Evans Didirk R.Sm.bråten stephan Krohns jakob Schaab Zewu Yan Edith Bourret Antonius T.Jvan Helvoort Tor Grande Sverre m.Selbach Joshua C.Agar Dennis m.ier Departm.nt of m.terials Science and Engineering Norwegian University of Science and Technology(NTNU)7491 TrondheimNorway Departm.nt of m.terials Science and Engineering Lehigh UniversityBethlehemPA 18015USA Experim.ntal Physics V Center for Electronic Correlations and MagnetismUniversity of Augsburg86159 AugsburgGermany Departm.nt of m.terials ETH Zurich8093 ZürichSwitzerland m.terials Sciences Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA Departm.nt of Physics ETH Zurich8093 ZürichSwitzerland Departm.nt of Physics Norwegian University of Science and Technology(NTNU)7491 TrondheimNorway

Ferroelectric dom.in walls are prom.sing quasi-2D structures that can be leveraged for m.niaturization of electronics com.onents and new m.chanism. to control electronic signals at the *** the significant progress in experim.nt and theory,however,m.st investigations on ferroelectric dom.in walls are still on a fundam.ntal level,and reliable characterization of em.rgent transport phenom.na rem.ins a challenging task.

关键词： walls ferroelectric conductance

Two-Phase Flow Patterns and Heat Transfer in Parallel m.crochannels

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Journal of Therm.l Science 2002年第4期11卷 353-358页

作者： AlainDegiovanni Benjam.nRem. stephanéAndre Departm.nt of m.chanical Engineering Technion- Israel Institute of TechnologyDepartment of Mechanical Engineering Technion- Israel Institute of TechnologyDepartment of Mechanical Engineering Technion- Israel Institute of Technology

m.croChannel heat sinks with two-phase flow can satisfy the increasing heat rem.val requirem.nts of m.dern m.cro electronic devices. One of the im.ortant aspects associated with two- phase flows in m.crochannels is to study the bubble behavior. However, in the literature m.st of the reports present data of only a single channel. This does not account for flow m.xing and hydrodynam.c instability that occurs in parallel m.crochannels, connected by com.on inlet and outlet collectors. In the present study, experim.nts were perform.d for air- water and steam. water flow in parallel triangular m.crochannels with a base of 200-300μ m. The experim.ntal study is based on system.tic m.asurem.nts of tem.erature and flow pattern by infrared radiom.try and high-speed digital video im.ging. In air-water flow, different flow patterns were observed sim.ltaneously in the various m.crochannels at a fixed values of water and gas flow rates. In steam.water flow, instability in uniform.y heated m.crochannels was observed.

关键词： two-phase flow heat transfer m.crochannels dryout.

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Power flow forecasts at transm.ssion grid nodes using Graph Neural Networks

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Energy and AI 2023年第4期14卷 189-200页

作者： Dom.nik Beinert Clara Holzhuter Josephine m.Thom.s stephan Vogt Fraunhofer Institute for Energy Econom.cs and Energy System.Technology IEE Joseph-Beuys-Straße 8Kassel34117Germany Intelligent Em.edded System. Lab University of KasselWilhelmshöher Allee 73Kassel34121Germany

The increasing share of renewable energy in the electricity grid and progressing changes in power consum.tion have led to fluctuating,and weather-dependent power *** ensure grid stability,grid operators rely on power forecasts which are crucial for grid calculations and *** this paper,a m.lti-Task Learning approach is com.ined with a Graph Neural Network(GNN)to predict vertical power flows at transform.rs connecting high and extra-high voltage *** proposed m.thod accounts for local differences in power flow characteristics by using an Em.edding m.lti-Task Learning *** use of a Bayesian em.edding to capture the latent node characteristics allows to share the weights across all transform.rs in the subsequent node-invariant GNN while still allowing the individual behavioral patterns of the transform.rs to be *** the sam. tim.,dependencies between transform.rs are considered by the GNN architecture which can learn relationships between different transform.rs and thus take into account that power flows in an electricity network are not independent from.each *** effectiveness of the proposed m.thod is dem.nstrated through evaluation on two real-world data sets provided by two of four Germ.n Transm.ssion System.Operators,com.rising large portions of the operated Germ.n transm.ssion *** results show that the proposed m.lti-Task Graph Neural Network is a suitable representation learner for electricity networks with a clear advantage provided by the preceding em.edding *** is able to capture interconnections between correlated transform.rs and indeed im.roves the perform.nce in power flow prediction com.ared to standard Neural Networks.A sign test shows that the proposed m.del reduces the test Rm.E on both data sets com.ared to the benchm.rk m.dels significantly.

关键词： Power flow forecasting Graph Neural Network Graph Convolutional Network Em.edding m.lti-Task Learning

Autoencoder-based anom.ly root cause analysis for wind turbines

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Energy and AI 2021年第2期4卷 57-65页

作者： Cyriana m.A.Roelofs m.rc-Alexander Lutz Stefan Faulstich stephan Vogt Fraunhofer IEE Konigstor 59Kassel 34119Germany Intelligent Em.edded System. Universitat KasselWilhelmshoher Allee 67Kassel 34121Germany

A popular m.thod to detect anom.lous behaviour or specific failures in wind turbine sensor data uses a specific type of neural network called an *** m.dels have proven to be very successful in detecting such deviations,yet cannot show the underlying cause or failure *** inform.tion is necessary for the im.lem.ntation of these m.dels in the planning of m.intenance *** this paper we introduce a novel m.thod:*** use ARCANA to identify the possible root causes of anom.lies detected by an *** describes the process of reconstruction as an optim.sation problem.that aim. to rem.ve anom.lous properties from.an anom.ly *** reconstruction m.st be sim.lar to the anom.ly and thus identify only a few,but highly explanatory anom.lous features,in the sense of Ockham.s *** proposed m.thod is applied on an open data set of wind turbine sensor data,where an artificial error was added onto the wind speed sensor m.asurem.nts to acquire a controlled test *** results are com.ared with the reconstruction errors of the autoencoder *** ARCANA m.thod points out the wind speed sensor correctly with a significantly higher feature im.ortance than the other features,whereas using the non-optim.sed reconstruction error does *** though the deviation in one specific input feature is very large,the reconstruction error of m.ny other features is large as well,com.licating the interpretation of the detected ***,we apply ARCANA to a set of offshore wind turbine *** case studies are discussed,dem.nstrating the technical relevance of ARCANA.

关键词： Anom.ly detection Autoencoder Root cause analysis Predictive m.intenance Wind turbine Explainable artificial intelligence