Jacob Biehl, Ph.D.

Senior Research Scientist

Jacob Biehl

Jacob’s research centers on building collaborative technologies that support natural and effective human-to-human communication. In this effort, his research spans many topics that include observing and building models of group dynamics and collaboration, distilling those models into the design and implementation of fully functional collaborative systems, and deploying technology into authentic work environments to understand their genuine impact on collaborative behavior. This approach has led to contributions that span many sub disciplines of computer science, including HCI, CSCW, distributed interactive systems, usable privacy, hardware sensing and more. He holds a B.S. in Statistics and Computer Science from the University of Illinois at Urbana-Champaign, where he also earned a M.S. and Ph.D. in Computer Science.

Co-Authors

Publications

2014
Publication Details
  • To appear in Ubicomp 2014
  • Sep 9, 2014

Abstract

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In recent years, there has been an explosion of social and collaborative applications that leverage location to provide users novel and engaging experiences. Current location technologies work well outdoors but fare poorly indoors. In this paper we present LoCo, a new framework that can provide highly accurate room-level location using a supervised classification scheme. We provide experiments that show this technique is orders of magnitude more efficient than current state-of-the-art Wi- Fi localization techniques. Low classification overhead and computational footprint make classification practical and efficient even on mobile devices. Our framework has also been designed to be easily deployed and lever- aged by developers to help create a new wave of location- driven applications and services.
2013
Publication Details
  • Future Generation Computer Systems
  • May 28, 2013

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Collaboration technologies must support information sharing between collaborators, but must also take care not to share too much information or share information too widely. Systems that share information without requiring an explicit action by a user to initiate the sharing must be particularly cautious in this respect. Presence systems are an emerging class of applications that support collaboration. Through the use of pervasive sensors, these systems estimate user location, activities, and available communication channels. Because such presence data are sensitive, to achieve wide-spread adoption, sharing models must reflect the privacy and sharing preferences of their users. This paper looks at the role that privacy-preserving aggregation can play in addressing certain user sharing and privacy concerns with respect to presence data. We define conditions to achieve CollaPSE (Collaboration Presence Sharing Encryption) security, in which (i) an individual has full access to her own data, (ii) a third party performs computation on the data without learning anything about the data values, and (iii) people with special privileges called “analysts” can learn statistical information about groups of individuals, but nothing about the individual values contributing to the statistic other than what can be deduced from the statistic. More specifically, analysts can decrypt aggregates without being able to decrypt the individual values contributing to the aggregate. Based in part on studies we carried out that illustrate the need for the conditions encapsulated by CollaPSE security, we designed and implemented a family of CollaPSE protocols. We analyze their security, discuss efficiency tradeoffs, describe extensions, and review more recent privacy-preserving aggregation work.

2012
Publication Details
  • IPIN2012
  • Nov 13, 2012

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We describe Explorer, a system utilizing mirror worlds - dynamic 3D virtual models of physical spaces that reflect the structure and activities of those spaces to help support navigation, context awareness and tasks such as planning and recollection of events. A rich sensor network dynamically updates the models, determining the position of people, status of rooms, or updating textures to reflect displays or bulletin boards. Through views on web pages, portable devices, or on 'magic window' displays located in the physical space, remote people may 'Clook in' to the space, while people within the space are provided with augmented views showing information not physically apparent. For example, by looking at a mirror display, people can learn how long others have been present, or where they have been. People in one part of a building can get a sense of activities in the rest of the building, know who is present in their office, and look in to presentations in other rooms. A spatial graph is derived from the 3D models which is used both to navigational paths and for fusion of acoustic, WiFi, motion and image sensors used for positioning. We describe usage scenarios for the system as deployed in two research labs, and a conference venue.

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Faithful sharing of screen contents is an important collaboration feature. Prior systems were designed to operate over constrained networks. They performed poorly even without such bottlenecks. To build a high performance screen sharing system, we empirically analyzed screen contents for a variety of scenarios. We showed that screen updates were sporadic with long periods of inactivity. When active, screens were updated at far higher rates than was supported by earlier systems. The mismatch was pronounced for interactive scenarios. Even during active screen updates, the number of updated pixels were frequently small. We showed that crucial information can be lost if individual updates were merged. When the available system resources could not support high capture rates, we showed ways in which updates can be effectively collapsed. We showed that Zlib lossless compression performed poorly for screen updates. By analyzing the screen pixels, we developed a practical transformation that significantly improved compression rates. Our system captured 240 updates per second while only using 4.6 Mbps for interactive scenarios. Still, while playing movies in fullscreen mode, our approach could not achieve higher capture rates than prior systems; the CPU remains the bottleneck. A system that incorporates our findings is deployed within the lab.
Publication Details
  • ACM Multimedia '12
  • Oct 29, 2012

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DisplayCast is a many to many screen sharing system that is targeted towards Intranet scenarios. The capture software runs on all computers whose screens need to be shared. It uses an application agnostic screen capture mechanism that creates a sequence of pixmap images of the screen updates. It transforms these pixmaps to vastly improve the lossless Zlib compression performance. These algorithms were developed after an extensive analysis of typical screen contents. DisplayCast shares the processor and network resources required for screen capture, compression and transmission with host applications whose output needs to be shared. It balances the need for high performance screen capture with reducing its resource interference with user applications. DisplayCast uses Zeroconf for naming and asynchronous location. It provides support for Cisco WiFi and Bluetooth based localization. It also includes a HTTP/REST based controller for remote session initiation and control. DisplayCast supports screen capture and playback in computers running Windows 7 and Mac OS X operating systems. Remote screens can be archived into a H.264 encoded movie on a Mac. They can also be played back in real time on Apple iPhones and iPads. The software is released under a New BSD license.
Publication Details
  • CHI 2012
  • May 7, 2012

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Affect influences workplace collaboration and thereby impacts a workplace's productivity. Participants in face-toface interactions have many cues to each other's affect, but work is increasingly carried out via computer-mediated channels that lack many of these cues. Current presence systems enable users to estimate the availability of other users, but not their affect states or communication preferences. This work investigates relationships between affect state and communication preferences and demonstrates the feasibility of estimating affect state and communication preferences from a presence state stream.
Publication Details
  • Fuji Xerox Technical Report No.21 2012
  • Feb 2, 2012

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Modern office work practices increasingly breach traditional boundaries of time and place, making it difficult to interact with colleagues. To address these problems, we developed myUnity, a software and sensor platform that enables rich workplace awareness and coordination. myUnity is an integrated platform that collects information from a set of independent sensors and external data aggregators to report user location, availability, tasks, and communication channels. myUnity's sensing architecture is component-based, allowing channels of awareness information to be added, updated, or removed at any time. Multiple channels of input are combined and composited into a single, high-level presence state. Early studies of a myUnity deployment have demonstrated that the platform allows quick access to core awareness information and show that it has become a useful tool for supporting communication and collaboration in the modern workplace.
Publication Details
  • Personal and Ubiquitous Computing (PUC)
  • Feb 1, 2012

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Presence systems are valuable in supporting workplace communication and collaboration. These systems are only effective if widely adopted and used. User perceptions of the utility of the information being shared and their comfort sharing such information strongly impact adoption and use. This paper describes the results of a survey of user preferences regarding comfort with and utility of workplace presence systems; the effects of sampling frequency, fidelity, and aggregation; and design implications of these results. We present new results that extend some past findings while challenging others. We contribute new design insights that inform the design of presence technologies to increase both utility and adoption.
2011
Publication Details
  • ACM Multimedia Industrial Exhibits
  • Nov 28, 2011

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Modern office work practices increasingly breach traditional boundaries of time and place, making it difficult to interact with colleagues. To address these problems, we developed myUnity, a software and sensor platform that enables rich workplace awareness and coordination. myUnity is an integrated platform that collects information from a set of independent sensors and external data aggregators to report user location, availability, tasks, and communication channels. myUnity's sensing architecture is component-based, allowing channels of awareness information to be added, updated, or removed at any time. Our current system includes a variety of sensor and data input, including camera-based activity classification, wireless location trilateration, and network activity monitoring. These and other input channels are combined and composited into a single, high-level presence state. Early studies of a myUnity deployment have demonstrated that use of the platform allows quick access to core awareness information and show it has become a useful tool supporting communication and collaboration in the modern workplace.

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Modern office work practices increasingly breach traditional boundaries of time and place, increasing breakdowns workers encounter when coordinating interaction with colleagues. We conducted interviews with 12 workers and identified key problems introduced by these practices. To address these problems we developed myUnity, a fully functional platform enabling rich workplace awareness and coordination. myUnity is one of the first integrated platforms to span mobile and desktop environments, both in terms of access and sensing. It uses multiple sources to report user location, availability, tasks, and communication channels. A pilot field study of myUnity demonstrated the significant value of pervasive access to workplace awareness and communication facilities, as well as positive behavioral change in day-to-day communication practices for most users. We present resulting insights about the utility of awareness technology in flexible work environments.
Publication Details
  • SECOTS 2011
  • May 23, 2011

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As sensors become ever more prevalent, more and more information will be collected about each of us. A longterm research question is how best to support beneficial uses while preserving individual privacy. Presence systems are an emerging class of applications that support collaboration. These systems leverage pervasive sensors to estimate end-user location, activities, and available communication channels. Because such presence data are sensitive, to achieve wide-spread adoption, sharing models must reflect the privacy and sharing preferences of the users. To reflect users' collaborative relationships and sharing desires, we introduce CollaPSE security in which an individual has full access to her own data, a third party processes the data without learning anything about the data values, and users higher up in the hierarchy learn only statistical information about the employees under them. We describe simple schemes that efficiently realize CollaPSE security for time series data. We implemented these protocols using readily available cryptographic functions, and integrated the protocols with FXPAL's MyUnity presence system.
2010
Publication Details
  • NPUC2010
  • Oct 22, 2010

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The massive amounts of information that are being collected about each of us will only increase as sensors become ever cheaper and more powerful. Analysis of this wealth of data supports advances in medicine and public health, improved software and services through user pattern analysis, and more efficient economic mechanisms. At the same time, the potential for misuse of such data is significant. A long-term research question is how best to support beneficial uses while inhibiting misuse. One approach is to enable individuals to maintain tighter control of their own data while still supporting the computation of group statistics. Currently, analysts are usually given access to all data in order to compute statistics, and often use a third party service provider to store, or even process, such data. Either the third party has access to all data or the data are encrypted, in which case the third party does no processing. An interesting research question is how to provide mechanisms to support "need to know" security in which an individual has full access to her own data, the third party learns nothing about the data but can nevertheless contribute to the processing, and the analyst learns only the desired statistics. We have explored "need to know" security in connection with MyUnity, a prototype awareness system. MyUnity collects data from a variety of sources and displays summary presence states, such as ``in office'' or ``with visitor,'' computed from the received data. MyUnity was deployed in a small research lab and has been in use by over 30 people for more than a year. To avoid concerns about misuse, the system did not store any data initially. The researchers developing the system were interested, however, in analyzing usage patterns, and users expressed interest in seeing personal trends, activity patterns of coworkers, and long-term data pooled across groups of users, all requiring data to be stored. At the same time, users continued to be concerned about misuse of stored data. We looked at ``need to know'' security for cases in which, at each time step, each member of a group of users has a value (i.e., a presence state) to contribute, and the group would like to provide only an aggregate view of those values to people outside their group. We designed and implemented an efficient protocol that enables each user to encrypt under her own key in such a way that a third party can compute an encryption of a sum across values encrypted under different keys without the need for further interactions with the individuals. The protocol provides means for an analyst to decrypt the encrypted sum. We designed key structures and extensions to provide a family of efficient non-interactive ``need to know'' protocols for time series data in which the analyst learns only the statistics, not the individual data values, and the third party learns nothing about the values.

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The use of whiteboards is pervasive across a wide range of work domains. But some of the qualities that make them successful—an intuitive interface, physical working space, and easy erasure—inherently make them poor tools for archival and reuse. If whiteboard content could be made available in times and spaces beyond those supported by the whiteboard alone, how might it be appropriated? We explore this question via ReBoard, a system that automatically captures whiteboard images and makes them accessible through a novel set of user-centered access tools. Through the lens of a seven week workplace field study, we found that by enabling new workflows, ReBoard increased the value of whiteboard content for collaboration.
Publication Details
  • In Proc. CHI 2010
  • Apr 10, 2010

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The modern workplace is inherently collaborative, and this collaboration relies on effective communication among coworkers. Many communication tools – email, blogs, wikis, Twitter, etc. – have become increasingly available and accepted in workplace communications. In this paper, we report on a study of communications technologies used over a one year period in a small US corporation. We found that participants used a large number of communication tools for different purposes, and that the introduction of new tools did not impact significantly the use of previously-adopted technologies. Further, we identified distinct classes of users based on patterns of tool use. This work has implications for the design of technology in the evolving ecology of communication tools.
Publication Details
  • Symposium on Eye Tracking Research and Applications 2010
  • Mar 22, 2010

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In certain applications such as radiology and imagery analysis, it is important to minimize errors. In this paper we evaluate a structured inspection method that uses eye tracking information as a feedback mechanism to the image inspector. Our two-phase method starts with a free viewing phase during which gaze data is collected. During the next phase, we either segment the image, mask previously seen areas of the image, or combine the two techniques, and repeat the search. We compare the different methods proposed for the second search phase by evaluating the inspection method using true positive and false negative rates, and subjective workload. Results show that gaze-blocked configurations reduced the subjective workload, and that gaze-blocking without segmentation showed the largest increase in true positive identifications and the largest decrease in false negative identifications of previously unseen objects.
2008
Publication Details
  • Workshop held in conjunction with CSCW2008
  • Nov 8, 2008

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It is increasingly common to find Multiple Display Environments (MDEs) in a variety of settings, including the workplace, the classroom, and perhaps soon, the home. While some technical challenges exist even in single-user MDEs, collaborative use of MDEs offers a rich set of opportunities for research and development. In this workshop, we will bring together experts in designing, developing, building and evaluating MDEs to improve our collective understanding of design guidelines, relevant real-world activities, evaluation methods and metrics, and opportunities for remote as well as collocated collaboration. We intend to create not only a broader understanding of this growing field, but also to foster a community of researchers interested in bringing these environments from the laboratory to the real world. In this workshop, we intended to explore the following research themes:
  • Elicitation and process of distilling design guidelines for MDE systems and interfaces.
  • Investigation and classification of activities suited for MDEs.
  • Exploration and assessment of how existing groupware theories apply to collaboration in MDEs.
  • Evaluation techniques and metrics for assessing effectiveness of prototype MDE systems and interfaces.
  • Exploration of MDE use beyond strictly collocated collaboration.