Network-Adaptive Video Communication Using Packet Path Diversity and Rate-Distortion Optimized Reference Picture Selection

In this paper, we present error-resilient Internet video transmission using path diversity and rate-distortion optimized reference picture selection. Under this scheme, the optimal packet dependency is determined adapting to network characteristics and video content, to achieve a better trade-off between coding efficiency and forming independent streams to increase error-resilience. The optimization is achieved within a rate-distortion framework, so that the expected end-to-end distortion is minimized under the given rate constraint. The expected distortion is calculated based on an accurate binary tree modeling with the effects of channel loss and error concealment taken into account. With the aid of active probing, packets are sent across multiple available paths according to a transmission policy which takes advantage of path diversity and seeks to minimize the loss rate. Experiments demonstrate that the proposed scheme provides significant diversity gain, as well as gains over video redundancy coding and the NACK mode of conventional reference picture selection. Yi Liang received the Ph.D. degree in Electrical Engineering from Stanford University in 2003. His expertise is in the areas of networked multimedia systems, real-time voice and video communication, and low-latency media streaming over the wire-line and wireless networks. Currently holding positions at Qualcomm CDMA Technologies, San Diego, CA, he is responsible for video and multimedia system design and development for Qualcomm's mobile station modem (MSM) chipsets. From 2000 to 2001, he conducted research with Netergy Networks, Inc., Santa Clara, CA, on voice over IP systems that provide improved quality over best-effort networks. From 2001 to 2003, he had been the lead of the Stanford - Hewlett-Packard Labs low-latency video streaming project, in which he and his colleagues developed error-resilience techniques for rich media communication over IP networks at low latency. In the summer of 2002 at Hewlett-Packard Labs, Palo Alto, CA, he developed an accurate loss-distortion model for compressed video and contributed in the development of the mobile streaming media content delivery network (MSM - CDN) that delivers rich media over 3G wireless. Yi Liang received the B. Eng. degree from Tsinghua University, Beijing, China. Eric Setton received the B.S. degree from Ecole Polytechnique, Palaiseau, France in 2001 and the M.S. degree, in Electrical Engineering from Stanford University in 2003. He is currently a Ph.D. candidate in the department of Electrical Engineering of Stanford University and is part of the Image, Video and Multimedia Systems group. Multimedia communication over wired and wireless networks, video compession and image processing are his main research interests. In 2001, he received the Carnot fellowship and the SAP Stanford Graduate fellowship. In 2003, he received the Sony SNRC fellowship. He has spent time in industry in France at SAGEM and in the United States at HP labs and at Sony Electronics. He has 4 patents pending. Bernd Girod is Professor of Electrical Engineering in the Information Systems Laboratory of Stanford University, California. He also holds a courtesy appointment with the StanfordDepartment of Computer Science and he serves as Director of the Image Systems Engineering Program at Stanford. His research interests include networked media systems, video signal compression and coding, and 3-d image analysis and synthesis. He received his M.S. degree in Electrical Engineering from Georgia Institute of Technology, in 1980 and his Doctoral degree “with highest honours” from University of Hannover, Germany, in 1987. Until 1987 he was a member of the research staff at the Institut fur Theoretische Nachrichtentechnik und Informationsverarbeitung, University of Hannover, working on moving image coding, human visual perception, and information theory. In 1988, he joined Massachusetts Institute of Technology, Cambridge, MA, USA, first as a Visiting Scientist with the Research Laboratory of Electronics, then as an Assistant Professor of Media Technology at the Media Laboratory. From 1990 to 1993, he was Professor of Computer Graphics and Technical Director of the Academy of Media Arts in Cologne, Germany, jointly appointed with the Computer Science Section of Cologne University. He was a Visiting Adjunct Professor with the Digital Signal Processing Group at Georgia Institute of Technology, Atlanta, GA, USA, in 1993. From 1993 until 1999, he was Chaired Professor of Electrical Engineering/Telecommunications at University of Erlangen-Nuremberg, Germany, and the Head of the Telecommunications Institute I, co-directing the Telecommunications Laboratory. He has served as the Chairman of the Electrical Engineering Department from 1995 to 1997, and as Director of the Center of Excellence “3-D Image Analysis and Synthesis” from 1995-1999. He has been a Visiting Professor with the Information Systems Laboratory of Stanford University, Stanford, CA, during the 1997/98 academic year. As an entrepreneur, Prof. Girod has worked successfully with several start-up ventures as founder, investor, director, or advisor. Most notably, he has been a co-founder and Chief Scientist of Vivo Software, Inc., Waltham, MA (1993–98); after Vivo's aquisition, 1998-2002, Chief Scientist of RealNetworks, Inc. (Nasdaq: RNWK); and, from 1996–2004, an outside Director of 8 × 8, Inc. (Nasdaq: EGHT). Prof. Girod has authored or co-authored one major text-book, two monographs, and over 250 book chapters, journal articles and conference papers in his field, and he holds about 20 international patents. He has served as on the Editorial Boards or as Associate Editor for several journals in his field, and is currently Area Editor for Speech, Image, Video and Signal Processing of the “IEEE Transactions on Communications.” He has served on numerous conference committees, e.g., as Tutorial Chair of ICASSP-97 in Munich and ICIP-2000 in Vancouver, as General Chair of the 1998 IEEE Image and Multidimensional Signal Processing Workshop in Alpbach, Austria, and as General Chair of the Visual Communication and Image Processing Conference (VCIP) in San Jose, CA, in 2001. Prof. Girod has been a member of the IEEE Image and Multidimensional Signal Processing Committee from 1989 to 1997 and was elected Fellow of the IEEE in 1998 ‘for his contributions to the theory and practice of video communications.’ He has been named ‘Distinguished Lecturer’ for the year 2002 by the IEEE Signal Processing Society. Together with J. Eggers, he is recipient of the 2002 EURASIP Best Paper Award.     

Dünnschicht‐Photovoltaik in Deutschland

Prospects for thin‐film PV in Germany Due to the German Energy Supply Act the photovoltaics market will continue to grow in Germany. The predicted fall in costs will require companies to implement a continuous improvement in efficiency while at the same time reducing process costs. This must be achieved by a constant increase in research performance. The aim here is the fastest possible reduction in power generation costs into or below the range of costs which can be reached with conventional energy carriers. In this respect the German industrial and research landscape is very well set up. Industry aspires to covering 12% of power requirements throughout Europe in by 2020 by means of photovoltaics [5]. At the present time in Germany less than 1% of power requirements is covered. For Germany the prospects are very good for taking up a leading role globally in thin‐film photovoltaics alongside the established crystalline silicon technology.     

A high blood level in the venous chamber and a wet‐stored dialyzer help to reduce exposure for microemboli during hemodialysis

During hemodialysis (HD), microemboli develop in the blood circuit of the apparatus. These microemboli can pass through the venous chamber and enter into the patient's circulation. The aim of this study was to investigate whether it is possible to reduce the risk for exposure of microemboli by altering of the treatment mode. Twenty patients on chronic HD were randomized to a prospective cross‐over study of three modes of HD: (a) a dry‐stored dialyzer (F8HPS, Fresenius, steam sterilized) with a low blood level in the venous chamber (DL), (b) the same dialyzer as above, but with a high level in the venous chamber (DH), and (c) a wet‐stored dialyzer (Rexeed, Asahi Kasei Medical, gamma sterilized) with a high blood level (WH). Microemboli measurements were obtained in a continuous fashion during 180 minutes of HD for all settings. A greater number of microemboli were detected during dialysis with the setting DL vs. WH (odds ratio [OR] 4.07, 95% confidence interval [CI] 4.03–4.11, P < 0.0001) and DH vs. WH (OR 1.18, 95% CI 1.17–1.19, P < 0.0001) and less for DH vs. DL (OR 0.290, 95% CI 0.288–0.293, P < 0.0001). These data indicate that emboli exposure was least when using WH, greater with DH, and most with DL. This study shows that using a high blood level in the venous chamber and wet‐stored dialyzers may reduce the number of microemboli.     

Structurally Based Assessment of the Influence of Fluorides on the Characteristics of Continuous Casting Powder Slags

The use of fluorides in continuous casting powder leads to the desired reduction of melting temperature to less than 1573 K (1300 °C) as well as to lowering the viscosity below 10 dPas. With an equilateral use of alkalis, the tendency to form volatile fluorine compounds rises. The effect of these components on the structure of the casting slags can be described with the NBO/T-ratio. Should the full effect of fluorides to be used for structural modification of the slags, the other components have to be inhibited by compound formation so as to prevent them from forming gaseous fluoride. If the fluoride content in the continuous casting slag is represented by means of fluorspar, the influence on the NBO/T-ratio can be described with the impact factor 4.0.     

Influence of sulfate solution concentration on the formation of gypsum in sulfate resistance test specimen

The sulfate concentration, which is required to form gypsum from portlandite, was derived from thermodynamical calculations and experimental measurements. The obtained results were compared to the sulfate concentrations in laboratory solutions that are commonly used to test the performance of concrete exposed to sulfate attack and also to sulfate concentrations that can be expected under field conditions. It was derived that the formation of gypsum can strongly affect the performance of binders in the tests, but has a less marked impact under most field conditions. An SEM investigation of mortar bars that were exposed to different sulfate concentrations supports the suggestion made.     

Microforming and investigation of parameter interactions

Microforming processes are significantly influenced by several process parameters. The research work covered in this paper investigates the interactions of some of these parameters and their impacts on the forming process. The impairment of formability and cavity filling are some typical results caused by miniaturizing the geometrical dimensions of the extruded form feature. The impact of an interaction on the forming result will be shown exemplarily with the temperature—pin diameter-interaction in more detail for a backward extrusion process. Additionally, the hardness distribution within the forming area will be investigated.     

Perceiving speed—The color can matter

This study focuses on examining color effects of perceived speed in an individual noncompetitive sport context, treadmill running. In addition, the presence of individual trends for color effects are inspected by observing the connection of color effects in a sport‐specific video rating task with those found in an individual color association task. For this, 32 participants rated the perceived running speed of 48 videos depicting runners on a treadmill at seven different speed settings. Furthermore, participants rated a range of additional sport‐specific performance parameters. The runners in the video were shown wearing either a red, blue, or gray jersey, gray being used to strengthen the cover story. As a secondary task, the participants performed a modified Stroop task to assess implicit color associations. The results showed a significant color effect for speed; runners depicted in red were perceived as running at higher speeds compared to blue. No significant color effects were found for the other sport‐specific parameters. Finally, there was no significant covariate effect of the modified Stroop task for the speed perception color effect. These findings indicate that, in situations in which speed must be judged, red might be perceived as going faster.