206793142
What video can and cannot do for collaboration: A case study
As multimedia become an integral part of collaborative systems, we must understand how to design such systems to support the user's rich set of existing interaction skills, rather than requiring people to adapt to arbitrary constraints of technology-driven designs. To understand how we can make effective use of video in remote collaboration, we compared a small team's interactions through a desktop video conferencing prototype with face-to-face interactions and phone conversations. We found that, compared with audio-only, the video channel of our desktop video conferencing prototype adds or improves the ability to show understanding, forecast responses, give nonverbal information, enhance verbal descriptions, manage pauses, and express attitudes. These findings suggest that video may be better than the phone for handling conflict and other interaction-intense activities. However, the advantages of video depend critically on the nearly-instantaneous transmission of audio, even if it means getting out of sync with the video image. Nonetheless, when compared with face-to-face interaction, it can be difficult in video interactions to notice peripheral cues, control the floor, have side conversations, point to things or manipulate real-world objects. To enable rich interactions fully, video should be integrated with other distributed tools that increase the extent and type of shared space in a way that enables natural collaborative behaviors within those environments.
1649407
Rhythm modeling, visualizations and applications
People use their awareness of others' temporal patterns to plan work activities and communication. This paper presents algorithms for programatically detecting and modeling temporal patterns from a record of online presence data. We describe analytic and end-user visualizations of rhythmic patterns and the tradeoffs between them. We conducted a design study that explored the accuracy of the derived rhythm models compared to user perceptions, user preference among the visualization alternatives, and users' privacy preferences. We also present a prototype application based on the rhythm model that detects when a person is "away" for an extended period and predicts their return. We discuss the implications of this technology on the design of computer-mediated communication.
6543572
Findings from Observational Studies of Collaborative Work
Abstract The work activity of small groups of three to four people was videotaped and analysed in order to understand collaborative work and to guide the development of tools to support it. The analysis focused on the group's shared drawing activity—their listing, drawing, gesturing and talking around a shared drawing surface. This analysis identified specific features of collaborative work activity that raise design implications for collaborative technology: (1) collaborators use hand gestures to uniquely communicate significant information; (2) the process of creating and using drawings conveys much information not contained in the resulting drawings; (3) the drawing space is an important resource for the group in mediating their collaboration; (4) there is a fluent mix of activity in the drawing space; and (5) the spatial orientation among the collaborators and the drawing space has a role in structuring their activity. These observations are illustrated with examples from the video data, and the design implications they raise are discussed.
6797006
Exploring web browser history comparisons
This work explores how comparing web navigation histories between two people and presenting the results to them might allow them to gain insight about each other. We developed a prototype that presents web matches sorted according to frequency, recency, and web site. Interviews with users of the prototype suggest that common interests and preferences can be inferred from these comparisons.
8944311
Recent shortcuts: using recent interactions to support shared activities
We present an empirical study of teams that revealed the amount of extraneous individual work needed to enable collaboration: finding references to other people, finding files to attach to email, managing incoming email attachments, managing the variety of files used in shared activities, and tracking what work is owed to others. Much of this work involves finding recently accessed objects that are needed again in the user's current task focus. These observations led to the design of Recent Shortcuts, a tool to help support coordination by making recently used objects easily accessible. Recent Shortcuts enables quick access to people (including groups of people), received attachments, files, and file folders that the user interacted with recently for re-use in the user's current context. Recent Shortcuts makes it easy to use these objects across applications with no additional user input and minimal changes to the user's applications or work practice. Early user experiences with a working prototype led to an extension that integrates recently accessed objects across multiple devices.
12875596
Exploring patterns of social commonality among file directories at work
We studied files stored by members of a work organization for patterns of social commonality. Discovering identical or similar documents, applications, developer libraries, or other files may suggest shared interests or experience among users. Examining actual file data revealed a number of individual and aggregate practices around file storage. For example, pairs of users typically have many (over 13,000) files in common. A prototype called LiveWire exploits this commonality to make file backup and restore more efficient for a work organization. We removed commonly shared files and focused on specific filetypes that represent user activity to find more meaningful files in common. The Consolidarity project explores how patterns of file commonality could encourage social networking in an organizational context. Mechanisms for addressing the privacy concerns raised by this approach are discussed.
46008282
A Head Gesture Recognition Algorithm
In this paper, we present a head gesture recognition algorithm that is based on the tracking technique developed by Kanade, Luca, and Tomasi (KaLuTo) and a one-class-in-one neural network algorithm. In our method, human skin colors are used to detect the head from complex backgrounds and the KaLuTo algorithm is applied to detect and track feature points on the head. Feature points tracked in successive frames are used to construct a feature vector as the input to the one-class-in-one neural network, which is employed to classify the head gestures into different classes. This method can offer some robustness to different background conditions. Experimental results prove the effectiveness of this method.
14586033
Dynamic Data-Driven Fault Diagnosis of Wind Turbine Systems
In this multi-university collaborative research, we will develop a framework for the dynamic data-driven fault diagnosis of wind turbines which aims at making the wind energy a competitive alternative in the energy market. This new methodology is fundamentally different from the current practice whose performance is limited due to the non-dynamic and non-robust nature in the modeling approaches and in the data collection and processing strategies. The new methodology consists of robust data pre-processing modules, interrelated, multi-level models that describe different details of the system behaviors, and a dynamic strategy that allows for measurements to be adaptively taken according to specific physical conditions and the associated risk level. This paper summarizes the latest progresses in the research.
16383417
Interference-aware routing in multihop wireless networks using directional antennas
Recent research has shown that interference can make a significant impact on the performance of multihop wireless networks. Researchers have studied interference-aware topology control recently [M. Burkhart et al., 2004]. In this paper, we study routing problems in a multihop wireless network using directional antennas with dynamic traffic. We present new definitions of link and path interference that are suitable for designing better routing algorithms. We then formulate and optimally solve two power constrained minimum interference single path routing problems. Routing along paths found by our interference-aware algorithms tends to have less channel collisions and higher network throughput. Our simulation results show that, compared with the minimum power path routing algorithm, our algorithms can reduce average path interference by 40% or more at the cost of a minor power increase. We also extend our work towards survivable routing by formulating and solving the power constrained minimum interference node-disjoint path routing problem.
39775533
Research of Atomic and Anonymous Electronic Commerce Protocol
Atomicity and anonymity are the two important requirements for application in electronic commerce. However absolutely anonymity may lead to confliction with law enforcement, e.g. blackmailing or money laundering. Therefore, it is important to design systems satisfying both atomicity and revocable anonymity. Based on the concept of two-phase commitment, we realize atomicity in electronic transaction with the Trusted Third Part as coordinator. Also we develops Brands' fair signature model, propose a method to enable not only anonymity but also owner-trace and money-trace.
15896075
Effective bandwidth-based QoS provisioning for real-time audio/video streaming over MIMO-OFDM wireless networks
We propose a cross-layer design scheme to support the real-time quality of service (QoS) guarantees for heterogeneous mobile users over downlink MIMO-OFDM wireless networks. Inspired by the effective bandwidth theory originally established for wired networks, we develop the approach to apply the theory into wireless networks. Based on MIMO-OFDM infrastructure employed at the physical (PHY)-layer, we analytically derive the medium access control (MAC)-layer admission-control and time-slot allocation algorithms to guarantee the statistical delay-bound for different real-time users. Simulation results show that the proposed scheme can efficiently support the wireless QoS requirement for diverse real-time mobile users.