Publications

FXPAL publishes in top scientific conferences and journals.

2006
Publication Details
  • UbiComp 2006 Workshop position paper
  • Sep 20, 2006

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We describe our work-in-progress: a "wizard-free" conference room designed for ease of use, yet retaining next-generation functionality. Called USE (Usable Smart Environments), our system uses multi-display systems, immersive conferencing, and secure authentication. It is based in cross-cultural ethnographic studies on the way people use conference rooms. The USE project has developed a flexible, extensible architecture specifically designed to enhance ease of use in smart environment technologies. The architecture allows customization and personalization of smart environments for particular people and groups, types of work, and specific physical spaces. The system consists of a database of devices with attributes, rooms and meetings that implements a prototype-instance inheritance mechanism through which contextual information (e.g. IP addresses application settings, phone numbers for teleconferencing systems, etc.) can be associated

Usable ubiquitous computing in next generation conference rooms: design, architecture and evaluation

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  • International workshop at UbiComp 2006.
  • Sep 17, 2006

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In the UbiComp 2005 workshop "Ubiquitous computing in next generation conference rooms" we learned that usability is one of the primary challenges in these spaces. Nearly all "smart" rooms, though they often have interesting and effective functionality, are very difficult to simply walk in and use. Most such rooms have resident experts who keep the room's systems functioning, and who often must be available on an everyday basis to enable the meeting technologies. The systems in these rooms are designed for and assume the presence of these human "wizards"; they are seldom designed with usability in mind. In addition, people don't know what to expect in these rooms; as yet there is no technology standard for next-generation conference rooms. The challenge here is to strike an effective balance between usability and new kinds of functionality (such as multiple displays, new interfaces, rich media systems, new uploading/access/security systems, robust mobile integration, to name just a few of the functions we saw in last year's workshop). So, this year, we propose a workshop to focus more specifically on how the design of next-generation conference rooms can support usability: the tasks facing the real people who use these rooms daily. Usability in ubiquitous computing has been the topic of several papers and workshops. Focusing on usability in next-generation conference rooms lets us bring to bear some of the insights from this prior work in a delineated application space. In addition the workshop will be informed by the most recent usability research in ubiquitous computing, rich media, context-aware mobile systems, multiple display environments, and interactive physical environments. We also are vitally concerned with how usability in smart environments tracks (or doesn't) across cultures. Conference room research has been and remains a focal point for some of the most interesting and applied work in ubiquitous computing. It is also an area where there are many real-world applications and daily opportunities for user feed-back: in short, a rich area for exploring usable ubiquitous computing. We see a rich opportunity to draw together researchers not only from conference room research but also from areas such as interactive furniture/smart environments, rich media, social computing, remote conferencing, and mobile devices for a lively exchange of ideas on usability in applied ubicomp systems for conference rooms.
Publication Details
  • International Conference on Pattern Recognition
  • Aug 20, 2006

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This paper describes a framework for detecting unusual events in surveillance videos. Most surveillance systems consist of multiple video streams, but traditional event detection systems treat individual video streams independently or combine them in the feature extraction level through geometric reconstruction. Our framework combines multiple video streams in the inference level, with a coupled hidden Markov Model (CHMM). We use two-stage training to bootstrap a set of usual events, and train a CHMM over the set. By thresholding the likelihood of a test segment being generated by the model, we build a unusual event detector. We evaluate the performance of our detector through qualitative and quantitative experiments on two sets of real world videos.
Publication Details
  • Interactive Video; Algorithms and Technologies Hammoud, Riad (Ed.) 2006, XVI, 250 p., 109 illus., Hardcover.
  • Jun 7, 2006

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This chapter describes tools for browsing and searching through video to enable users to quickly locate video passages of interest. Digital video databases containing large numbers of video programs ranging from several minutes to several hours in length are becoming increasingly common. In many cases, it is not sufficient to search for relevant videos, but rather to identify relevant clips, typically less than one minute in length, within the videos. We offer two approaches for finding information in videos. The first approach provides an automatically generated interactive multi-level summary in the form of a hypervideo. When viewing a sequence of short video clips, the user can obtain more detail on the clip being watched. For situations where browsing is impractical, we present a video search system with a flexible user interface that incorporates dynamic visualizations of the underlying multimedia objects. The system employs automatic story segmentation, and displays the results of text and image-based queries in ranked sets of story summaries. Both approaches help users to quickly drill down to potentially relevant video clips and to determine the relevance by visually inspecting the material.

Visualization in Audio-Based Music Information Retrieval

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  • Computer Music Journal Vol. 30, Issue 2, pp. 42-62, 2006.
  • Jun 6, 2006

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Music Information Retrieval (MIR) is an emerging research area that explores how music stored digitally can be effectively organized, searched, retrieved and browsed. The explosive growth of online music distribution, portable music players and lowering costs of recording indicate that in the near future most of recorded music in human history will be available digitally. MIR is steadily growing as a research area as can be evidenced by the international conference on music information retrieval (ISMIR) series soon in its sixth year and the increasing number of MIR-related publications in the Computer Music Journal as well as other journals and conferences.
Publication Details
  • Complexity, Vol 11, No 5.
  • Jun 3, 2006

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Technology-the collection of devices and methods available to human society-evolves by constructing new devices and methods from ones that previously exist, and in turn offering these as possible components-building blocks-for the construction of further new devices and elements. The collective of technology in this way forms a network of elements where novel elements are created from existing ones and where more complicated elements evolve from simpler ones. We model this evolution within a simple artificial system on the computer. The elements in our system are logic circuits. New elements are formed by combination from simpler existing elements (circuits), and if a novel combination satisfies one of a set of needs it is retained as a building block for further combination. We study the properties of the resulting buildout. We find that our artificial system can create complicated technologies (circuits), but only by first creating simpler ones as building blocks. Our results mirror Lenski et al.'s, that complex features can be created in biological evolution only if simpler functions are first favored and act as stepping stones. We also find evidence that the resulting collection of technologies exists at self-organized criticality.
Publication Details
  • Proceedings of AVI '06 (Short Paper), ACM Press, pp. 258-261.
  • May 23, 2006

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During grouping tasks for data exploration and sense-making, the criteria are normally not well-defined. When users are bringing together data objects thought to be similar in some way, implicit brushing continually detects for groups on the freeform workspace, analyzes the groups' text content or metadata, and draws attention to related data by displaying visual hints and animation. This provides helpful tips for further grouping, group meaning refinement and structure discovery. The sense-making process is further enhanced by retrieving relevant information from a database or network during the brushing. Closely related to implicit brushing, target snapping provides a useful means to move a data object to one of its related groups on a large display. Natural dynamics and smooth animations also help to prevent distractions and allow users to concentrate on the grouping and thinking tasks. Two different prototype applications, note grouping for brainstorming and photo browsing, demonstrate the general applicability of the technique.
Publication Details
  • The 15th International World Wide Web Conference (WWW2006)
  • May 23, 2006

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In a landmark article, over a half century ago, Vannevar Bush envisioned a "Memory Extender" device he dubbed the "memex". Bush's ideas anticipated and inspired numerous breakthroughs, including hypertext, the Internet, the World Wide Web, and Wikipedia. However, despite these triumphs, the memex has still not lived up to its potential in corporate settings. One reason is that corporate users often don't have sufficient time or incentives to contribute to a corporate memory or to explore others' contributions. At FXPAL, we are investigating ways to automatically create and retrieve useful corporate memories without any added burden on anyone. In this paper we discuss how ProjectorBox a smart appliance for automatic presentation capture and PAL Bar a system for proactively retrieving contextually relevant corporate memories have enabled us to integrate content from a variety of sources to create a cohesive multimedia corporate memory for our organization.

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.
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  • 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.