19772221
A real-time interactive virtual classroom multimedia distance learning system
In this paper, we present the design and development of a real-time interactive virtual classroom multimedia distance learning system at the University of Washington. There has been rapid progress in digital media compression research, and the delivery of media data on the public Internet is becoming widespread. A real-time interactive virtual classroom allows a remote participant to not only receive a live class feed, but also to interact in a live class by asking questions with audio, video in real-time using an Internet connection. Many instructors use electronically prepared slides during their class. The traditional video coding algorithms are not able to compress this slide data very well at low bit-rates. We propose a Web-based real-time presentation system for the electronic slides. Instructors also write text on a white board or a piece of paper during the class. At low bit-rates, conventional video encoding algorithms cannot encode this handwritten text video with enough fidelity, resulting in an illegible decoded video. We propose an extension of the well known bilevel image encoding algorithms to handle the handwritten text video. Our method results in decoded video frames which can be read very clearly when encoded at low bit-rates. We have developed a set of tools which allows recording the live classroom session and automatic creation of a synchronized multimedia integration language (SMIL) presentation, which can be used for a later viewing.
19195717
Automatic creation of a talking head from a video sequence
In this paper, a real-time system to create a talking head from a video sequence without any user intervention is presented. In the proposed system, a probabilistic approach, to decide whether or not extracted facial features are appropriate for creating a three-dimensional (3-D) face model, is presented. Automatically extracted two-dimensional facial features from a video sequence are fed into the proposed probabilistic framework before a corresponding 3-D face model is built to avoid generating an unnatural or nonrealistic 3-D face model. To extract face shape, we also present a face shape extractor based on an ellipse model controlled by three anchor points, which is accurate and computationally cheap. To create a 3-D face model, a least-square approach is presented to find a coefficient vector that is necessary to adapt a generic 3-D model into the extracted facial features. Experimental results show that the proposed system can efficiently build a 3-D face model from a video sequence without any user intervention for various Internet applications including virtual conference and a virtual story teller that do not require much head movements or high-quality facial animation.
2727201
Analyzing ENUM Service and Administration from the Bottom Up: The addressing system for IP telephony and beyond
ENUM creates many new market opportunities and raises several important policy issues related to the implementation and administration of the ENUM database and services. Recent World Telecommunications Policy Forum 2001 dealt with the emergence of ENUM as an important numbering issue of IP telephony. This paper prepares some important emerging issues of ENUM administration and policy by taking an empirical research approach from the bottom up. 
We will identify potential key ENUM services, and estimating the size of the service market opportunities created by the availability of PSTN-IP addressing and mapping mechanisms, particularly in the context of IP telephony. Also, we analyze the possible administrative models and relationship scenarios among different ENUM players such as Registry(ies), Registrars, Telephone Service Providers, ENUM Application Service Providers, etc. Then, we will assess the effects of various administrative model architectures of ENUM service by looking at the market opportunities and motivations of the players. From the empirical findings, we will draw the implications on transactions among different kinds of ENUM service providers. Finally, the results of the model analysis will be used for the discussion of policy related issues around the ENUM and IP telephony services. 
Keywords: IP Telephony, ENUM, Internet Policy, Numbering and Addressing System, Service and Market Study, Administration Model, Empirical Market Study.
12033624
Computing motif correlations in proteins
Protein motifs, which are specific regions and conserved regions, are found by comparing multiple protein sequences. These conserved regions in general play an important role in protein functions and protein folds, for example, for their binding properties or enzymatic activities. The aim here is to find the existence correlations of protein motifs. The knowledge of protein motif/domain sharing should be important in shedding new light on the biologic functions of proteins and offering a basis in analyzing the evolution in the human genome or other genomes. The protein sequences used here are obtained from the PIR-NREF database and the protein motifs are retrieved from the PROSITE database. We apply data mining approach to discover the occurrence correlations of motif in protein sequences. The correlation of motifs mined can be used in evolution analyses and protein structure prediction. We discuss the latter, i.e., protein structure prediction in this study. The correlations mined are stored and maintained in a database system. The database is now available at http://bioinfo.csie.ncu.edu.tw/ProMotif/.
16037350
Interprovider differentiated service interconnection management models in the Internet bandwidth commodity markets
Due to the recent evolution of telecommunications infrastructure and the Internet as a commodity market for bandwidth, Internet Service Providers (ISPs) encounter new issues concerned with bandwidth management for the network interconnection. Bandwidth commodity exchange is considered a new B2B (Business-to-Business) electronic commerce application that brings new market opportunities to carriers and service providers for managing their bandwidth resources. This paper develops market-based bandwidth management optimization models for Differentiated Service (DiffServ) QoS (Quality of Service) networks using an implementation of the bandwidth management agent, BMP (Bandwidth Management Point). We use network economic models to formulate an optimization problem for the interconnection and resource allocation policy of the DiffServ network. We formulate and develop those economic models as optimization problems of LP, NLP, MILP and mixed integer nonlinear programming (MINLP), and discuss the pricing mechanisms and available solution approaches for the implementation of the BMP's resource optimization process. Different opportunity costs are estimated based on the results of a network simulation using traffic flow statistics measured from a recent Internet backbone. We then numerically simulate the behavior of backbone network ISPs to optimize their profits for various demand scenarios.