Sponsored by. CorporateSponsors

. ACM Multi medi a Systems 2015 wi th NOSSDAV .MMVE .MOVI D 18 -20 MARCH 2015,Portland,USA Sponsored by I n Cooperati on Wi th CorporateSponsors ...
Author: Shona Ramsey
1 downloads 3 Views 1MB Size
.

ACM Multi medi a Systems 2015

wi th NOSSDAV .MMVE .MOVI D 18 -20 MARCH 2015,Portland,USA

Sponsored by

I n Cooperati on Wi th

CorporateSponsors

Program Highlights The 6th ACM Multimedia Systems Conference

Keynote March 18, 2015, Wednesday 0845-1000 Venue: Skyline II Keynote Speaker: Oscar Nestares, Intel Corp. Changing the Paradigm of Imaging Through Immersive Media Experiences Abstract: In this talk we will explore how the evolution of photography and personal media has reached an inflection point in its evolution. Recent developments of imaging systems have created rich immersive data sets that allow for new forms of media and interaction with our digital environment. We will give a glimpse into research at Intel Labs that explores new computational imaging capabilities in the area of multi-camera systems and interactive visual experiences. We will highlight new imaging technologies that made their way from research into recent Intel products, and what capabilities these offer to the researchers and developers. In closing, we will give an outlook on where we see this trend to go and the opportunities this offers for research in computational imaging. Bio: Oscar Nestares is the Technical Lead and manager of the Expressive Imaging Lab (part of the Computational Imaging Lab in Intel Labs), which is in charge of researching and developing algorithms for computational photography applications. Oscar was a graduate student from 1994 to 1998 at the Institute of Optics (Spanish National Research Council, or CSIC) working on image sequences representation, texture analysis, optical flow estimation, and multiframe image denosing. He received his M.S. and Ph.D. in Electrical Engineering from Universidad Politecnica de Madrid in 1994 and 1997. From 1998 to 2000, he was a Visiting Scholar at Stanford University, developing robust methods for magnetic resonance volumes registration. During the same period he was a consultant at Xerox PARC, working on statistical methods for motion estimation. From 2000 to 2003, he was a tenured Research Scientist at the Institute of Optics (CSIC), working on probabilistic models of visual acuity with application to optical pattern recognition in blurred images. In 2003 he joined Intel. Since then, he has been working on statistical approaches to video enhancement (de-noising, superresolution, and stabilization), its applications to consumer electronics, workload analysis, and computational photography.

The 6th ACM Multimedia Systems Conference

Augmented Reality Demonstration March 19, 2015, Thursday 1415-1600 Venue: Skyline I Display Anywhere Interactive Data Visualization by Intel Labs Carl S. Marshall, Selvakumar Panneer, Cindy Chung, Janet Tseng, Kathy Yuen, and Nico Galoppo Abstract: Intel Labs developed technology to allow any surface to be transformed into an interactive display. This demo showcases photos and videos from social media projected onto a large wall display, featuring user interaction similar to that of a tablet but in a more natural environment. In this demo, we invite users to learn about multiple aspect of the ACM MMSys conference and other ACM conferences through an intuitive interface. Our technology will hope to inspire new experiences to share, interact, and discover multimedia.

The 6th ACM Multimedia Systems Conference

Banquet March 19, 2015, Thursday 1930-2230 BridgePort Brewpub 1313 NW Marshall St, Portland, OR. Directions from Hilton Portland & Executive Tower • Walk to the Central Library Streetcar Station for NS Line (about 6 min, 0.2 mi) • Take NS Line towards NW 23rd Ave (about 13 min, 9 stops) • Alight at NW Northrup & 14th Streetcar Station • Walk along NW 14th towards NW 14th & Marshall St. (about 1 min) Two streetcar tickets are included in your conference package. If you prefer to walk, the walk from Hilton Portland & Executive Tower to BridgePort Brewpub takes only 25 mins.

The 25th ACM Workshop on Network and Operating Systems Support for Digital Audio and Video

25th Anniversary Panel March 20, 2015, Friday 1300-1415 Venue: Skyline II For the 25th anniversary of NOSSDAV, we are pleased to have a panel of distinguished researchers that have published papers in the first 10 years of NOSSDAV. We invite you to hear these researchers reflect on the areas they were working on in the 1990s , how the area has evolved, and their words of wisdom on the future of NOSSDAV. • Networking - Kevin Almeroth, University of California - Santa Barbara • Operating Systems - Prashant Shenoy, University of Massachusetts • Real-time Systems - Kevin Jeffay, University of North Carolina (remote participation) • Middleware and Applications - Ketan Mayer-Patel, University of North Carolina • Streaming and Coding - Wu-chi Feng, Portland State University

The 7th ACM Mobile Video Workshop

Keynote March 20, 2015, Friday 0830-0930 Venue: Skyline III Keynote Speaker: Vana Kalogeraki, Athens University of Economics and Business Real-Time Reliable Crowdsourcing Techniques for the Mobile Urban Crowd Abstract: The widespread adoption of smartphones, the ubiquitous sensing capabilities and the prevalence of location based services are ushering in the participatory sensing era where people take active roles in sensing, instrumenting and analyzing aspects of their lives online, creating virtual communities, changing their social and working habits. In this talk we will discuss the exciting opportunities in utilizing the human crowd and pushing computation and data storage as much as possible to mobile devices, integrating participatory sensing and crowdsourcing techniques in the development of sophisticated urban applications. Specifically I will present a number of research challenges and novel crowdsourcing techniques that aim to exploit the wisdom of the human crowd to achieve both high quality results and meet real-time constraints. Bio: Vana Kalogeraki is an Associate Professor at Athens University of Economics and Business in Greece where she is leading the Distributed and Real-Time Systems research. Previously she has held positions as an Associate and Assistant Professor at the Department of Computer Science at the University of California, Riverside and as a Research Scientist at Hewlett-Packard Labs in Palo Alto. She has been working in the field of distributed and real-time systems, participatory sensing systems, distributed sensor systems, peer-to-peer systems, resource management and fault-tolerance for over 15 years. She has published over 140 journal and conference papers and contributions to books. She has served as the General co-Chair of SEUS 2009 and WPDRTS 2006, Program co-Chair of MDM 2011, ISORC 2009, ISORC 2007, ICPS 2005, WPDRTS 2005 and DBISP2P 2003, in addition to other roles such as Area Chair (IEEE ICDCS 2012) and as program committee member on over 150 conferences. She was invited to give keynote talks at DNCMS 2012, SN2AE 2012, PETRA 2011, DBISP2P 2006 and MLSN 2006 in the areas of participatory sensing systems and sensor network middleware. She was awarded an ERC Starting/Consolidator grant, a Marie Curie Fellowship, two best paper awards at IPDPS 2009, SAINT 2008, a best student paper award at SAINT 2011 and a best student paper runner-up award at MDM 2014. More information about her work can be found at: http://www.cs.aueb.gr/~vana

Technical Program The 6th ACM Multimedia Systems Conference March 18, 2015, Wednesday Venue: Skyline II 0830-0845

Opening Remarks

0845-1000

Keynote Chair: Feng Liu, Portland State University Changing the Paradigm of Imaging Through Immersive Media Experiences Oscar Nestares, Intel Corpoeration

1000-1030

Coffee Break

1030-1200

Session 1: Mobile Chair: Pablo Cesar, CWI LBVC: Towards Low-Bandwidth Video Chat on Smartphones Xin Qi, College of William and Mary Qing Yang, College of William and Mary David T. Nguyen, College of William and Mary Gang Zhou, College of William and Mary Ge Peng, College of William and Mary Video Composition by the Crowd: A System to Compose User-Generated Videos in Near Real-Time Stefan Wilk, TU Darmstadt Stephan Kopf, University of Mannheim Wolfgang Effelsberg, TU Darmstadt EMOD: An Efficient On-Device Mobile Visual Search System Dawei Li, Lehigh University Mooi Choo Chuah, Lehigh University

1200-1315

Lunch Venue: Skyline I

1315-1445

Session 2: Clouds and CDN Chair: Carsten Griwodz, University of Oslo and Simula Laboratory Optimizing the Video Transcoding Workflow in Content Delivery Networks Dilip Kumar Krishnappa, University of Massachusetts Amherst Michael Zink, University of Massachusetts Amherst Ramesh Sitaraman, University of Massachusetts Amherst & Akamai Technologies

Transcoding Live Adaptive Video Streams at a Massive Scale in the Cloud Ramon Aparicio-Pardo, Telecom Bretagne Karine Pires, Telecom Bretagne Alberto Blanc, Telecom Bretagne Gwendal Simon, Telecom Bretagne SmoothCache 2.0: CDN-quality Adaptive HTTP Live Streaming on Peer-To-Peer Overlays Roberto Roverso, Hive Inc. Riccardo Reale, Hive Inc. Sameh El-Ansary, Hive Inc. Seif Haridi, Royal Institute of Technology-KTH 1415-1600

Coffee Break / Technical Demonstration / AR Demo Venue: Skyline I Expert Driven Semi-Supervised Elucidation Tool for Medical Endoscopic Videos Zeno Albisser, Simula Research Laboratory Michael Riegler, Simula Research Laboratory Pål Halvorsen, Simula Research Laboratory Jiang Zhou, Dublin City University Carsten Griwodz, Simula Research Laboratory Ilangko Balasingham, Oslo University Hospital & University of Oslo Cathal Gurrin, Dublin City University Merge and Forward - Self-Organized Inter-Destination Multimedia Synchronization Benjamin Rainer, Alpen-Adria-Universität Klagenfurt Stefan Petscharnig, Alpen-Adria-Universität Klagenfurt Christian Timmerer, Alpen-Adria-Universität Klagenfurt Energy Efficient Video Encoding Using the Tegra K1 Mobile Processor Kristoffer Robin Stokke, Simula Research Laboratory & University of Oslo Håkon Kvale Stensland, Simula Research Laboratory & University of Oslo Carsten Griwodz, Simula Research Laboratory & University of Oslo Pål Halvorsen, Simula Research Laboratory & University of Oslo Media Download Optimization Through Prefetching and Resource Allocation in Mobile Networks Christian Koch, Technische Universität Darmstadt Nicola Bui, IMDEA Networks Institute & Universidad Carlos III de Madrid Julius Rückert, Technische Universität Darmstadt Guido Fioravantti, IMDEA Networks Institute & Universidad Carlos III de Madrid Foivos Michelinakis, IMDEA Networks Institute & Universidad Carlos III de Madrid Stefan Wilk, Technische Universität Darmstadt Joerg Widmer, IMDEA Networks Institute David Hausheer, Technische Universität Darmstadt How Much Delay Is There Really in Current Games? Kjetil Raaen, Westerdals Oslo School of Arts & Simula/University of Oslo Andreas Petlund, Simula Research Laboratory Scaling Virtual Camera Services to a Large Number of Users Vamsidhar Reddy Gaddam, Simula Research Laboratory & University of Oslo Ragnar Langseth, Simula Research Laboratory & University of Oslo Håkon Kvale Stensland, Simula Research Laboratory & University of Oslo Carsten Griwodz, Simula Research Laboratory & University of Oslo Dag Johansen, University of Tromsø Pål Halvorsen, Simula Research Laboratory & University of Oslo

Rhizome: Utilizing the Public Cloud to Provide 3D Gaming Infrastructure Ryan Shea, Simon Fraser University Di Fu, Simon Fraser University Jiangchuan Liu, Simon Fraser University Video BenchLab Demo: An Open Platform for Realistic Benchmarking of Streaming Media Workloads Patrick Pegus II, University of Massachusetts Amherst Emmanuel Cecchet, University of Massachusetts Amherst Prashant Shenoy, University of Massachusetts Amherst 1600-1730

Special Session on Augmented Reality Chair: Carl S. Marshall, Intel Corp. and Jonathan Ventura, University of Colorado Colorado Springs Content First - a Concept for Industrial Augmented Reality Maintenance Applications Using Mobile Devices Timo Engelke, Fraunhofer IGD Jens Keil, Fraunhofer IGD Pavel Rojtberg, Fraunhofer IGD Folker Wientapper, Fraunhofer IGD Ulrich Bockholt, Fraunhofer IGD MMT+AVR: Enabling Collaboration in Augmented Virtuality/Reality Using ISO’s MPEG Media Transport Karthik Venkatraman, University of Texas at Dallas Yuan Tian, University of Texas at Dallas Suraj Raghuraman, University of Texas at Dallas Balakrishnan Prabhakaran, University of Texas at Dallas Nhut Nguyen, TIN Consulting Depth-Disparity Calibration for Augmented Reality on Binocular Optical See-Through Displays Wanmin Wu, Ricoh Innovations Corp. Ivana Tošić, Ricoh Innovations Corp. Kathrin Berkner, Ricoh Innovations Corp. Nikhil Balram, Ricoh Innovations Corp.

1830-2100

Reception Venue: Pavilion Ballroom

March 19, 2015, Thursday Venue: Skyline II 0830-1000

Session 3: Streaming Chair: Ketan Mayer-Patel, University of North Carolina Congestion-Aware MAC Layer Adaptation to Improve Video Teleconferencing Over Wi-Fi Wei Chen, InterDigital Communications Liangping Ma, InterDigital Communications Chien-Chung Shen, University of Delaware

Integrated Prefetching and Caching for Adaptive Video Streaming Over HTTP: An Online Approach Ke Liang, Advanced Digital Sciences Center Jia Hao, National University of Singapore Roger Zimmermann, National University of Singapore David K.Y. Yau, Singapore University of Technology and Design Dynamic Configuration of Single Frequency Networks in Mobile Streaming Systems Saleh Almowuena, Simon Fraser University Mohamed Hefeeda, Simon Fraser University 1000-1030

Coffee Break

1030-1200

Session 4: Measurement and Performance Chair: Gwendal Simon, Telecom Bretagne Video BenchLab: An Open Platform for Realistic Benchmarking of Streaming Media Workloads Patrick Pegus II, University of Massachusetts Amherst Emmanuel Cecchet, University of Massachusetts Amherst Prashant Shenoy, University of Massachusetts Amherst Screencast Dissected: Performance Measurements and Design Considerations Chih-Fan Hsu, Academia Sinica Tsung-Han Tsai, Academia Sinica Chun-Ying Huang, National Taiwan Ocean University Cheng-Hsin Hsu, National Tsing Hua University Kuan-Ta Chen, Academia Sinica Analysis and Characterization of a Video-On-Demand Service Workload Ahmed Ali-Eldin, Umeå University Maria Kihl, Lund University Johan Tordsson, Umeå University Erik Elmroth, Umeå University

1200-1315

Lunch Venue: Skyline I

1315-1445

Dataset Track I Chair: Pål Halvorsen, Simula Research Laboratory & University of Oslo Multi-Sensor Concert Recording Dataset Including Professional and User-Generated Content Werner Bailer, Joanneum Research Chris Pike, BBC Research & Development Rik Bauwens, Vlaamse Radio- en Televisieomroeporganisatie Reinhard Grandl, Bitmovin Mike Matton, Vlaamse Radio- en Televisieomroeporganisatie Marcus Thaler, Joanneum Research Div150Cred: A Social Image Retrieval Result Diversification With User Tagging Credibility Dataset Bogdan Ionescu, University Politehnica of Bucharest Adrian Popescu, CEA LIST Mihai Lupu, Vienna University of Technology Alexandru Lucian Gînscă, CEA LIST Bogdan Boteanu, University Politehnica of Bucharest Henning Müller, HES-SO Sierre

A Scalable Video Coding Dataset and Toolchain for Dynamic Adaptive Streaming Over HTTP Christian Kreuzberger, Alpen-Adria-Universität Klagenfurt Daniel Posch, Alpen-Adria-Universität Klagenfurt Hermann Hellwagner, Alpen-Adria-Universität Klagenfurt 1445-1545

Coffee Break / Open Poster Session Venue: Skyline Foyer Class-Act: Datasets from a Human Posture/Activity Classification Investigation Presented by: John Kemp, Converty University Energy and Performance Optimisation of a Simple Video Encoder on the Jetson-TK1 Presented by: Kristoffer Robin Stokke, University of Oslo / Simula Research Laboratory The Cameraman Operating My Virtual Camera Is Artificial: Can The Machine Be As Good As A Human? Presented by: Vamsidhar Reddy Gaddam, University of Oslo / Simula Research Laboratory

1545-1715

Dataset Track II Chair: Michael Alexander Riegler, Simula Research Laboratory RAISE - a Raw Images Dataset for Digital Image Forensics Duc-Tien Dang-Nguyen, University of Cagliari Cecilia Pasquini, University of Trento Valentina Conotter, University of Trento Giulia Boato, University of Trento YouTube Live and Twitch: A Tour of User-Generated Live Streaming Systems Karine Pires, Telecom Bretagne Gwendal Simon, Telecom Bretagne The Toulouse Vanishing Points Dataset Vincent Angladon, Université de Toulouse & Telequid Simone Gasparini, Université de Toulouse Vincent Charvillat, Université de Toulouse Stanford I2V: A News Video Dataset for Query-By-Image Experiments André Araujo, Stanford University Jason Chaves, Stanford University David Chen, Stanford University Roland Angst, Stanford University Bernd Girod, Stanford University Data Set of Fall Events and Daily Activities From Inertial Sensors Olukunle Ojetola, Coventry University Elena Gaura, Coventry University James Brusey, Coventry University A Multi-Lens Stereoscopic Synthetic Video Dataset Fan Zhang, Portland State University Wu-chi Feng, Portland State University Feng Liu, Portland State University

1715-1730

Closing Remarks

1930-2230

Banquet Venue: BridgePort Brewpub, 1313 NW Marshall St.

The 25th ACM Workshop on Network and Operating Systems Support for Digital Audio and Video (NOSSDAV) March 20, 2015, Friday Venue: Skyline II 0830-0845

Opening Remarks

0845-1015

Session 1: QoE Chair: Michael Zink, University of Massachusetts Amherst Content-Adaptive Display Power Saving in Internet Mobile Streaming Yao Liu, SUNY Binghamton Mengbai Xiao, George Mason University Ming Zhang, George Mason University Xin Li, Samsung Telecommunications America Mian Dong, AT International, Inc. Zhan Ma, Nanjing University Zhenhua Li, Tsinghua University Songqing Chen, George Mason University Exploitation of Producer Intent in Relation to Bandwidth and QoE for Online Video Streaming Services Michael Riegler, University of Oslo and Simula Research Laboratory Lilian Calvet, University of Oslo and Simula Research Laboratory Amandine Calvet, University of Oslo and Simula Research Laboratory Pål Halvorsen, University of Oslo and Simula Research Laboratory Carsten Griwodz, University of Oslo and Simula Research Laboratory When On-The-Fly Erasure Code Makes Late Video Decoding Happen Pierre Ugo, Tournoux, University of La Réunion Tuan Tran Thai, University of Toulouse Emmanuel Lochin, University of Toulouse Jé́rôme Lacan, University of Toulouse Last N: Relevance-Based Selectivity for Forwarding Video in Multimedia Conferences Boris Grozev, Jitsi.org Lyubomir Marinov, Jitsi.org Varun Singh, Aalto University Emil Ivov, Jitsi.org

1015-1045

Coffee Break

1045-1200

Session 2: Streaming Chair: Songqing Chen, George Mason University DASH Fast Start Using HTTP/2 Wael Cherif, Canon Research Centre France Youenn Fablet, Canon Research Centre France Eric Nassor, Canon Research Centre France Jonathan Taquet, Canon Research Centre France Yuki Fujimori, Canon Inc. A Fuzzy-Based Rate Adaptation Controller for DASH Ashkan Sobhani, University of Ottawa Abdulsalam Yassine, University of Ottawa Shervin Shirmohammadi, University of Ottawa VAS: A Video Adaptation Service to Support Mobile Video Stefan Wilk, TU Darmstadt Denny Stohr, TU Darmstadt Wolfgang Effelsberg, TU Darmstadt

1200-1300

Lunch

1300-1415

NOSSDAV 25th Anniversary Panel

1415-1515

Session 3: Beyond Streaming Chair: Christian Timmerer, Alpen-Adria-Universität Klagenfurt Thunder Crystal: A Novel Crowdsourcing-Based Content Distribution Platform Liang Chen, Shenzhen University Yipeng Zhou, Shenzhen University Mi Jing, Xunlei Network Technology Company Richard T.B. Ma, National University of Singapore A Logical Memory Model for Scaling Parallel Multimedia Workloads Preben N. Olsen, University of Oslo and Simula Research Laboratory Martin Nyhus, University of Oslo and Simula Research Laboratory Pål Halvorsen, University of Oslo and Simula Research Laboratory Carsten Griwodz, University of Oslo and Simula Research Laboratory

1515-1545

Coffee Break

1545-1700

Session 4: Games Chair: Gwendal Simon, Telecom Bretagne On Crowdsourced Interactive Live Streaming: A Twitch.TV-Based Measurement Study Cong Zhang, Simon Fraser University Jiangchuan Liu, Simon Fraser University Towards Bridging Online Game Playing and Live Broadcasting: Design and Optimization Ryan Shea, Simon Fraser University Di Fu, Simon Fraser University Jiangchuan Liu, Simon Fraser University A Taxonomy for Player Actions With Latency in Network Games Mark Claypool, Worcester Polytechnic Institute Tianhe Wang, Worcester Polytechnic Institute McIntyre Watts, Worcester Polytechnic Institute

The 7th ACM Workshop on Mobile Video (MoVid) March 20, 2015, Friday Venue: Skyline III 0825-0830 0830-0930

Opening Remarks Keynote Chair: Nikil Dutt, University of California, Irvine Real-Time Reliable Crowdsourcing Techniques for the Mobile Urban Crowd Vana Kalogeraki, Athens University of Economics and Business

0930-1030

Session: Adaptive Video Delivery Chair: Pål Halvorsen, University of Oslo / Simula Research Laboratory (Not) Yet Another Policy for Scalable Video Delivery to Mobile Users S. Amir Hosseini, NYU Polytechnic School of Engineering Fraida Fund, NYU Polytechnic School of Engineering Shivendra S. Panwar, NYU Polytechnic School of Engineering Real-Time Video Quality Analysis on Mobile Devices Hannes Fassold, Joanneum Research Stefanie Wechtitsch, Joanneum Research Marcus Thaler, Joanneum Research Krzysztof Kozlowski, Joanneum Research Werner Bailer, Joanneum Research Adaptive Video Streaming for UAV Networks Severin Kacianka, Alpen-Adria-Universität Klagenfurt Hermann Hellwagner, Alpen-Adria-Universität Klagenfurt

1030-1050

Coffee Break

1050-1210

Session: Energy Efficiency Chair: Håkon Kvale Stensland, University of Oslo / Simula Research Laboratory Complexity Constrained Layering of Broadcast Video for Heterogeneous Mobile Receivers Mohsen Jamali Langroodi, Simon Fraser University Joseph Peters, Simon Fraser University Shervin Shirmohammadi, University of Ottawa Towards Energy-Aware DASH for Mobile Video Mohammad Hosseini, University of Illinois at Urbana-Champaign Anduo Wang, University of Illinois at Urbana-Champaign Rasoul Etesami, University of Illinois at Urbana-Champaign Spatio-Temporal Visual Security Metric for Secure Mobile Video Applications Junhyung Moon, Yonsei University Kyoungwoo Lee, Yonsei University Energy Efficient Continuous Multimedia Processing Using the Tegra K1 Mobile SoC Kristoffer Robin Stokke, University of Oslo / Simula Research Laboratory Håkon Kvale Stensland, University of Oslo / Simula Research Laboratory Carsten Griwodz, University of Oslo / Simula Research Laboratory Pål Halvorsen, University of Oslo / Simula Research Laboratory

The 7th ACM Workshop on Massively Multiuser Virtual Environments (MMVE) March 20, 2015, Friday Venue: Skyline IV 0900-0910

Opening Remarks

0910-1015

Session 1: Scalability, Consistency, and Improvement Chair: Jean Botev, University of Luxembourg Scalable Concurrency Control for Massively Collaborative Virtual Environments Patrick Lange, University of Bremen Rene Weller, University of Bremen Gabriel Zachmann, University of Bremen Predicting Object Lifetimes in Finite Distributed Storage Systems Under Churn John Gilmore, Stellenbosch University Herman Engelbrecht, Stellenbosch University Budget Based Dynamic State Update Aggregation Lutz Behnke, HAW Hamburg Qi Wang, University of the West of Scotland Christos Grecos, University of the West of Scotland Kai von Luck, HAW Hamburg

1015-1045

Coffee Break

1045-1150

Session 2: Algorithm, Networking, and Optimization Chair: Herman Engelbrecht, Stellenbosch University Coordinated Bandwidth Adaptations for Distributed 3D Tele-Immersive Systems Mohammad Hosseini, University of Illinois at Urbana-Champaign Gregorij Kurillo, University of California at Berkeley Network Support for Social 3-D Immersive Tele-Presence With Highly Realistic Natural and Synthetic Avatar Users Rufael Mekuria, Centrum Wiskunde & Informatica Antonella Frisiello, Istituto Superiore Mario Boella Marco Pasin, Istituto Superiore Mario Boella Pablo Cesar, Centrum Wiskunde & Informatica Structural Balance and Optimized Connectivity in Peer-To-Peer Massively Multiuser Virtual Environments Jean Botev, University of Luxembourg