Publications

FXPAL publishes in top scientific conferences and journals.

2006

Tunnel Vector: A New Routing Algorithm with Scalability

Publication Details
  • The 9th IEEE Global Internet Symposium in conjunction with the 25th IEEE INFOCOM Conference, Barcelona, Catalunya, Spain, April 28 - 29, 2006
  • Apr 28, 2006

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Routing algorithms such as Distance Vector and Link States have the routing table size as O(n), where n is the number of destination identifiers, thus providing only limited scalability for large networks when n is high. As the distributed hash table (DHT) techniques are extraordinarily scalable with n, our work aims at adapting a DHT approach to the design of a network-layer routing algorithm so that the average routing table size can be significantly reduced to O(log n) without losing much routing efficiency. Nonetheless, this scheme requires a major breakthrough to address some fundamental challenges. Specifically, unlike a DHT, a network-layer routing algorithm must (1) exchange its control messages without an underlying network, (2) handle link insertion/deletion and link-cost updates, and (3) provide routing efficiency. Thus, we are motivated to propose a new network-layer routing algorithm, Tunnel Vector (TV), using DHT-like multilevel routing without an underlying network. TV exchanges its control messages only via physical links and is self-configurable in response to linkage updates. In TV, the routing path of a packet is near optimal while the routing table size is O(log n) per node, with high probability. Thus, TV is suitable for routing in a very large network.
Publication Details
  • Proceedings of ACM DIS (Designing Interactive Systems) 2006, Penn State, Penn.
  • Apr 5, 2006

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What does a student need to know to be a designer? Beyond a list of separate skills, what mindset does a student need to develop for designerly action now and into the future? In the excitement of the cognitive revolution, Simon proposed a way of thinking about design that promised to make it more manageable and cognitive: to think of design as a planning problem. Yet, as Suchman argued long ago, planning accounts may be applied to problems that are not at base accomplished by planning, to the detriment of design vision. This paper reports on a pedagogy that takes Suchman's criticism to heart and avoids dressing up design methods as more systematic and predictive than they in fact are. The idea is to teach design through expo-sure to not just one, but rather, many methods---that is, sets of rules or behaviors that produce artifacts for further reflec-tion and development. By introducing a large number of design methods, decoupled from theories, models or frame-works, we teach (a) important cross-methodological regu-larities in competence as a designer, (b) that the practice of design can itself be designed and (c) that method choice affects design outcomes. This provides a rich and produc-tive notion of design particularly necessary for the world of pervasive and ubiquitous computing.
Publication Details
  • EACL (11th Conference of the European Chapter of the Association for Computational Linguistics)
  • Apr 3, 2006

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Probabilistic Latent Semantic Analysis (PLSA) models have been shown to provide a better model for capturing polysemy and synonymy than Latent Semantic Analysis (LSA). However, the parameters of a PLSA model are trained using the Expectation Maximization (EM) algorithm, and as a result, the trained model is dependent on the initialization values so that performance can be highly variable. In this paper we present a method for using LSA analysis to initialize a PLSA model. We also investigated the performance of our method for the tasks of text segmentation and retrieval on personal-size corpora, and present results demonstrating the efficacy of our proposed approach.
Publication Details
  • International Journal of Web Services Practices
  • Jan 17, 2006

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Mobile users often require access to their documents while away from the office. While pre-loading documents in a repository can make those documents available remotely, people need to know in advance which documents they might need. Furthermore, it may be difficult to view, print, or share the document through a portable device such as cell phone. We describe DoKumobility, a network of web services for mobile users for managing, printing, and sharing documents. In this paper, we describe the infrastructure and illustrate its use with several applications. We conclude with a discussion of lessons learned and future work.
2005

On-Demand Overlay Networking of Collaborative Applications

Publication Details
  • IEEE CollaborateCom 2005 - The First IEEE International Conference on Collaborative Computing: Networking, Applications and Worksharing
  • Dec 19, 2005

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We propose a new overlay network, called Generic Identifier Network (GIN), for collaborative nodes to share objects with transactions across affiliated organizations by merging the organizational local namespaces upon mutual agreement. Using local namespaces instead of a global namespace can avoid excessive dissemination of organizational information, reduce maintenance costs, and improve robustness against external security attacks. GIN can forward a query with an O(1) latency stretch with high probability and achieve high performance. In the absence of a complete distance map, its heuristic algorithms for self configuration are scalable and efficient. Routing tables are maintained using soft-state mechanisms for fault tolerance and adapting to performance updates of network distances. Thus, GIN has significant new advantages for building an efficient and scalable Distributed Hash Table for modern collaborative applications across organizations.
Publication Details
  • Proceedings of SPIE International Symposium ITCom 2005 on Multimedia Systems and Applications VIII, Boston, Massachusetts, USA, October 2005.
  • Dec 7, 2005

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Meeting environments, such as conference rooms, executive briefing centers, and exhibition spaces, are now commonly equipped with multiple displays, and will become increasingly display-rich in the future. Existing authoring / presentation tools such as PowerPoint, however, provide little support for effective utilization of multiple displays. Even using advanced multi-display enabled multimedia presentation tools, the task of assigning material to displays is tedious and distracts presenters from focusing on content. This paper describes a framework for automatically assigning presentation material to displays, based on a model of the quality of views of audience members. The framework is based on a model of visual fidelity which takes into account presentation content, audience members' locations, the limited resolution of human eyes, and display location, orientation, size, resolution, and frame rate. The model can be used to determine presentation material placement based on average or worst case audience member view quality, and to warn about material that would be illegible. By integrating this framework with a previous system for multi-display presentation [PreAuthor, others], we created a tool that accepts PowerPoint and/or other media input files, and automatically generates a layout of material onto displays for each state of the presentation. The tool also provides an interface allowing the presenter to modify the automatically generated layout before or during the actual presentation. This paper discusses the framework, possible application scenarios, examples of the system behavior, and our experience with system use.
Publication Details
  • Video track, ACM Multimedia 2005.
  • Nov 13, 2005

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A Post-Bit is a prototype of a small ePaper device for handling multimedia content, combining interaction control and display into one package. Post-Bits are modeled after paper Post-Its™; the functions of each Post-Bit combine the affordances of physical tiny sticky memos and digital handling of information. Post-Bits enable us to arrange multimedia contents in our embodied physical spaces. Tangible properties of paper such as flipping, flexing, scattering and rubbing are mapped to controlling aspects of the content. In this paper, we introduce the integrated design and functionality of the Post-Bit system, including four main components: the ePaper sticky memo/player, with integrated sensors and connectors; a small container/binder that a few Post-Bits can fit into, for ordering and multiple connections; the data and power port that allows communication with the host com-puter; and finally the software and GUI interface that reside on the host PC and manage multimedia transfer.
Publication Details
  • ACM Multimedia 2005, Technical Demonstrations.
  • Nov 5, 2005

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The MediaMetro application provides an interactive 3D visualization of multimedia document collections using a city metaphor. The directories are mapped to city layouts using algorithms similar to treemaps. Each multimedia document is represented by a building and visual summaries of the different constituent media types are rendered onto the sides of the building. From videos, Manga storyboards with keyframe images are created and shown on the façade; from slides and text, thumbnail images are produced and subsampled for display on the building sides. The images resemble windows on a building and can be selected for media playback. To support more facile navigation between high overviews and low detail views, a novel swooping technique was developed that combines altitude and tilt changes with zeroing in on a target.

Seamless presentation capture, indexing, and management

Publication Details
  • Internet Multimedia Management Systems VI (SPIE Optics East 2005)
  • Oct 26, 2005

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Technology abounds for capturing presentations. However, no simple solution exists that is completely automatic. ProjectorBox is a "zero user interaction" appliance that automatically captures, indexes, and manages presentation multimedia. It operates continuously to record the RGB information sent from presentation devices, such as a presenter's laptop, to display devices, such as a projector. It seamlessly captures high-resolution slide images, text and audio. It requires no operator, specialized software, or changes to current presentation practice. Automatic media analysis is used to detect presentation content and segment presentations. The analysis substantially enhances the web-based user interface for browsing, searching, and exporting captured presentations. ProjectorBox has been in use for over a year in our corporate conference room, and has been deployed in two universities. Our goal is to develop automatic capture services that address both corporate and educational needs.
Publication Details
  • World Conference on E-Learning in Corporate, Government, Healthcare, & Higher Education (E-Learn 2005)
  • Oct 24, 2005

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Automatic lecture capture can help students, instructors, and educational institutions. Students can focus less on note-taking and more on what the instructor is saying. Instructors can provide access to lecture archives to help students study for exams and make-up missed classes. And online lecture recordings can be used to support distance learning. For these and other reasons, there has been great interest in automatically capturing classroom presentations. However, there is no simple solution that is completely automatic. ProjectorBox is our attempt to create a "zero user interaction" appliance that automatically captures, indexes, and manages presentation multimedia. It operates continuously to record the RGB information sent from presentation devices, such as an instructor's laptop, to display devices such as a projector. It seamlessly captures high-resolution slide images, text, and audio. A web-based user interface allows students to browse, search, replay, and export captured presentations.
Publication Details
  • In Proceedings of International Conference on Computer Vision, 2005, page 1026-1033
  • Oct 17, 2005

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Recent years have witnessed the rise of many effective text information retrieval systems. By treating local visual features as terms, training images as documents and input images as queries, we formulate the problem of object recognition into that of text retrieval. Our formulation opens up the opportunity to integrate some powerful text retrieval tools with computer vision techniques. In this paper, we propose to improve the efficiency of articulated object recognition by an Okapi-Chamfer matching algorithm. The algorithm is based on the inverted index technique. The inverted index is a widely used way to effectively organize a collection of text documents. With the inverted index, only documents that contain query terms are accessed and used for matching. To enable inverted indexing in an image database, we build a lexicon of local visual features by clustering the features extracted from the training images. Given a query image, we extract visual features and quantize them based on the lexicon, and then look up the inverted index to identify the subset of training images with non-zero matching score. To evaluate the matching scores in the subset, we combined the modified Okapi weighting formula with the Chamfer distance. The performance of the Okapi-Chamfer matching algorithm is evaluated on a hand posture recognition system. We test the system with both synthesized and real world images. Quantitative results demonstrate the accuracy and efficiency our system.
Publication Details
  • IEEE Trans. Multimedia, Vol. 7 No. 5, pp. 981-990
  • Oct 11, 2005

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Abstract-We present a system for automatically extracting the region of interest and controlling virtual cameras control based on panoramic video. It targets applications such as classroom lectures and video conferencing. For capturing panoramic video, we use the FlyCam system that produces high resolution, wide-angle video by stitching video images from multiple stationary cameras. To generate conventional video, a region of interest (ROI) can be cropped from the panoramic video. We propose methods for ROI detection, tracking, and virtual camera control that work in both the uncompressed and compressed domains. The ROI is located from motion and color information in the uncompressed domain and macroblock information in the compressed domain, and tracked using a Kalman filter. This results in virtual camera control that simulates human controlled video recording. The system has no physical camera motion and the virtual camera parameters are readily available for video indexing.
Publication Details
  • http://www.strata.com/gallery_detail.asp?id=1480&page=1&category=48
  • Oct 1, 2005

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I produced these Illustrations for two multimedia applications that were developed by FX Palo Alto Laboratory and California State University at Sacramento's Department of Psychology. The applications were part of a study to see how primary school age children learn with certain multimedia tools. Each illustration was viewed as part of a fairly complex screen of information as well as on its own.
Publication Details
  • We organized and ran a full-day workshop at the UbiComp 2005 Conference in Tokyo, Japan, September 11, 2005.
  • Sep 29, 2005

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Designing the technologies, applications, and physical spaces for next-generation conference rooms (This is a day-long workshop in Tokyo.) Next-generation conference rooms are often designed to anticipate the onslaught of new rich media presentation and ideation systems. Throughout the past couple of decades, many researchers have attempted to reinvent the conference room, aiming at shared online or visual/virtual spaces, smart tables or walls, media support and tele-conferencing systems of varying complexity. Current research in high-end room systems often features a multiplicity of thin, bright display screens (both large and small), along with interactive whiteboards, robotic cameras, and smart remote conferencing systems. Added into the mix one can find a variety of meeting capture and metadata management systems, automatic or not, focused on capturing different aspects of meetings in different media: to the Web, to one's PDA or phone, or to a company database. Smart spaces and interactive furniture design projects have shown systems embedded in tables, podiums, walls, chairs and even floors and lighting. Exploiting the capabilities of all these technologies in one room, however, is a daunting task. For example, faced with three or more display screens, all but a few presenters are likely to opt for simply replicating the same image on all of them. Even more daunting is the design challenge: how to choose which capabilities are vital to particular tasks, or for a particular room, or are well suited to a particular culture. In this workshop we'll explore how the design of next-generation conference rooms can be informed by the most recent research in rich media, context-aware mobile systems, ubiquitous displays, and interactive physical environments. How should conference room systems reflect the rapidly changing expectations around personal devices and smart spaces? What kinds of systems are needed to support meetings in technologically complex environments? How can design of conference room spaces and technologies account for differing social and cultural practices around meetings? What requirements are imposed by security and privacy issues in public spaces? What aspects of meeting capture and access technologies have proven to be useful, and how should a smart environment enable them? What intersections exist with other research areas such as digital libraries? Conference room research has been and remains a focal point for some of the most interesting and applied work in ubiquitous computing. What lessons can we take from the research to date as we move forward? We are confident that a lively and useful discussion will be engendered by bringing directions from recent ubicomp research in games, multimedia applications, and social software to ongoing research in conference rooms systems: integrating architecture and tangible media, information design and display, and mobile and computer-mediated communications.
Publication Details
  • Paper presented at SIGGRAPH 2005, Los Angeles.
  • Sep 29, 2005

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The Convertible Podium is a central control station for rich media in next-generation classrooms. It integrates flexible control systems for multimedia software and hardware, and is designed for use in classrooms with multiple screens, multiple media sources and multiple distribution channels. The built-in custom electronics and unique convertible podium frame allows intuitive conversion between use modes (either manual or automatic). The at-a-touch sound and light control system gives control over the classroom environment. Presentations can be pre-authored for effective performance, and quickly altered on the fly. The counter-weighted and motorized conversion system allows one person to change modes simply by lifting the top of the Podium to the correct position for each mode. The Podium is lightweight, mobile, and wireless, and features an onboard 21" LCD display, document cameras and other capture devices, tangible controls for hardware and software, and also possesses embedded RFID sensing for automatic data retrieval and file management. It is designed to ease the tasks involved in authoring and presenting in a rich media classroom, as well as supporting remote telepresence and integration with other mobile devices.
Publication Details
  • INTERACT '05 short paper
  • Sep 12, 2005

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Indexes such as bookmarks and recommendations are helpful for accessing multimedia documents. This paper describes the 3D Syllabus system, which is designed to visualize indexes to multimedia training content along with the information structures. A double-sided landscape with balloons and cubes represents the personal and group indexes, respectively. The 2D ground plane organizes the indexes as a table and the third dimension of height indicates their importance scores. Additional visual properties of the balloons and cubes provide other information about the indexes and their content. Paths are represented by pipes connecting the balloons. A reliminary evaluation of the 3D Syllabus prototype suggests that it is more efficient than a typical training CD-ROM and is more enjoyable to use.
Publication Details
  • INTERACT 2005, LNCS 3585, pp. 781-794
  • Sep 12, 2005

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A video database can contain a large number of videos ranging from several minutes to several hours in length. Typically, it is not sufficient to search just for relevant videos, because the task still remains to find the relevant clip, typically less than one minute of length, within the video. This makes it important to direct the users attention to the most promising material and to indicate what material they already investigated. Based on this premise, we created a video search system with a powerful and flexible user interface that incorporates dynamic visualizations of the underlying multimedia objects. The system employes an automatic story segmentation, combines text and visual search, and displays search results in ranked sets of story keyframe collages. By adapting the keyframe collages based on query relevance and indicating which portions of the video have already been explored, we enable users to quickly find relevant sections. We tested our system as part of the NIST TRECVID interactive search evaluation, and found that our user interface enabled users to find more relevant results within the allotted time than other systems employing more sophisticated analysis techniques but less helpful user interfaces.
Publication Details
  • M.F. Costabile and F. Paternò (Eds.): INTERACT 2005, LNCS 3585
  • Sep 12, 2005

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We developed and studied an experimental system, RealTourist, which lets a user to plan a conference trip with the help of a remote tourist consultant who could view the tourist's eye-gaze superimposed onto a shared map. Data collected from the experiment were analyzed in conjunction with literature review on speech and eye-gaze patterns. This inspective, exploratory research identified various functions of gaze-overlay on shared spatial material including: accurate and direct display of partner's eye-gaze, implicit deictic referencing, interest detection, common focus and topic switching, increased redundancy and ambiguity reduction, and an increase of assurance, confidence, and understanding. This study serves two purposes. The first is to identify patterns that can serve as a basis for designing multimodal human-computer dialogue systems with eye-gaze locus as a contributing channel. The second is to investigate how computer-mediated communication can be supported by the display of the partner's eye-gaze.
Publication Details
  • Short presentation in UbiComp 2005 workshop in Tokyo, Japan.
  • Sep 11, 2005

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As the use of rich media in mobile devices and smart environments becomes more sophisticated, so must the design of the everyday objects used as containers or controllers. Rather than simply tacking electronics onto existing furniture or other objects, the design of a smart object can enhance existing ap-plications in unexpected ways. The Convertible Podium is an experiment in the design of a smart object with complex integrated systems, combining the highly designed look and feel of a modern lectern with systems that allow it to serve as a central control station for rich media manipulation in next-generation confer-ence rooms. It enables easy control of multiple independent screens, multiple media sources (including mobile devices) and multiple distribution channels. The Podium is designed to ease the tasks involved in authoring and presenting in a rich media meeting room, as well as supporting remote telepresence and in-tegration with mobile devices.
Publication Details
  • Demo and presentation in UbiComp 2005 workshop in Tokyo, Japan.
  • Sep 11, 2005

Abstract

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A Post-Bit is a prototype of a small ePaper device for handling multimedia content, combining interaction control and display into one package. Post-Bits are modeled after paper Post-Its™; the functions of each Post-Bit combine the affordances of physical tiny sticky memos and digital handling of information. Post-Bits enable us to arrange multimedia contents in our embodied physical spaces. Tangible properties of paper such as flipping, flexing, scattering and rubbing are mapped to controlling aspects of the content. In this paper, we introduce the integrated design and functionality of the Post-Bit system, including four main components: the ePaper sticky memo/player, with integrated sensors and connectors; a small container/binder that a few Post-Bits can fit into, for ordering and multiple connections; the data and power port that allows communication with the host com-puter; and finally the software and GUI interface that reside on the host PC and manage multimedia transfer.
Publication Details
  • Sixteenth ACM Conference on Hypertext and Hypermedia
  • Sep 6, 2005

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Hyper-Hitchcock is a hypervideo editor enabling the direct manipulation authoring of a particular form of hypervideo called "detail-on-demand video." This form of hypervideo allows a single link out of the currently playing video to provide more details on the content currently being presented. The editor includes a workspace to select, group, and arrange video clips into several linear sequences. Navigational links placed between the video elements are assigned labels and return behaviors appropriate to the goals of the hypervideo and the role of the destination video. Hyper-Hitchcock was used by students in a Computers and New Media class to author hypervideos on a variety of topics. The produced hypervideos provide examples of hypervideo structures and the link properties and behaviors needed to support them. Feedback from students identified additional link behaviors and features required to support new hypervideo genres. This feedback is valuable for the redesign of Hyper-Hitchcock and the design of hypervideo editors in general.

DoKumobility: Web services for the mobile worker

Publication Details
  • IEEE International Conference on Next Generation Web Services Practices (NWeSP'05), Seoul, Korea
  • Aug 22, 2005

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Mobile users often require access to their documents while away from the office. While pre-loading documents in a repository can make those documents available remotely, people need to know in advance which documents they might need. Furthermore, it may be difficult to view, print, or share the document through a portable device such as cell phone. We implemented DoKumobility, a network of web services for mobile users for managing, printing, and sharing documents. In this paper, we describe the infrastructure and illustrate its use with several applications