Wetlands are among the most productive natural ecosystems in the world, generally being important biodiversity hotspots. However, the complex nature of these landscapes together with the fragile and dynamic relationships among the organisms inhabiting these regions, make wetland ecosystems especially vulnerable to environmental disturbance, such as climate change. Thus, developing new automated systems which allow continuous monitoring and mapping of wetland dynamics is crucial for preserving their natural health. Synthetic aperture radar (SAR) systems have proven useful in monitoring and mapping the hydrological processes of wetland ecosystems through the use of polarimetric change detection techniques. Nonetheless, most of these flood change detectors rely on static detection approaches, generally covering a limited period of time (e.g., pre and post flooding scenario comparison), thus failing in providing continuous information about the diverse hydrological mechanisms. In this context, this research presents a novel approach for monitoring the hydrological dynamics of wetlands in a continuous and near-real-time manner using dense Sentinel-1 image time-series. In this work, we have enhanced our recently developed algorithm based on cumulative sums (SAR-CUSUM), to include polarimetric information, which allows to classify the type of change due to the flood. The new processing stack exploits the polarimetric information of dual-pol Sentinel-1 dense time series for detecting floods and provide some separation between open water and flooded vegetation areas. The outcomes derived from this study emphasize the capabilities of dense SAR time-series for environmental monitoring while providing a useful tool which could be integrated into rapid response and wetland conservation management plans.

A diversity of user goals and strategies make creation-oriented applications such as word processors or photo-editors difficult to comprehensively test. Evaluating such applications requires testing a large pool of participants to capture the diversity of experience, but traditional usability testing can be prohibitively expensive. To address this problem, this article contributes a new usability evaluation method called backtracking analysis, designed to automate the process of detecting and characterizing usability problems in creation-oriented applications. The key insight is that interaction breakdowns in creation-oriented applications often manifest themselves in backtracking operations that can be automatically logged (e.g., undo and erase operations). Backtracking analysis synchronizes these events to contextual data such as screen capture video, helping the evaluator to characterize specific usability problems. The results from three experiments demonstrate that backtracking events can be effective indicators of usability problems in creation-oriented applications, and can yield a cost-effective alternative to traditional laboratory usability testing.

One approach to reducing the costs of usability testing is to facilitate the automatic detection of critical incidents: serious breakdowns in interaction that stand out during software use. This research evaluates the use of undo and erase events as indicators of critical incidents in Google SketchUp (a 3D-modeling application), measuring an indicator's usefulness by the numbers and types of usability problems discovered. We compared problems identified using undo and erase events to problems identified using the user-reported critical incident technique [Hartson and Castillo 1998]. In a within-subjects experiment with 35 participants, undo and erase episodes together revealed over 90% of the problems rated as severe, several of which would not have been discovered by self-report alone. Moreover, problems found by all three methods were rated as significantly more severe than those identified by only a subset of methods. These results suggest that undo and erase events will serve as useful complements to user-reported critical incidents for low cost usability evaluation of creation-oriented applications like SketchUp.

Participatory Design is a design approach that provides a popular set of techniques for designing interactive systems in collaboration with end-users. Technology probes are one of such techniques, developed recently to encourage users' engagement with design ideas while capturing interaction. In this paper, we describe a technology probe called Zebra, which aimed at exploring the design of an observation tool for fieldwork with busy professionals. We deployed Zebra in the coffee room of our lab and observed researchers' reactions to the proposed concepts it embodied, both as researchers and as participants. We found that participants engaged with the probe in ways ranging from playful performances, through to abandoning the social space. Based on analysis of the collected qualitative and quantitative data, we present our reflections on the Zebra probe, how it eased the burden of engagement in the design process, and helped us better understand the potential of the observation tool for participatory design with busy professionals.

The availability of a good interface for online user collaboration has been a sore point for most collaboration applications to date. While MUD’s, MOO’s, IRC and other chat applications are well suited to impersonal communication, the meaning of a single message can often be misconstrued or misunderstood, and the effort often required to learn control of a new application while understanding navigation in a virtual world, can be difficult to overcome. The Nexus promises to aid in the intuitive act of communication, interaction and movement and in the process enhance the collaboration experience for the user, through the use of a game engine.

With increasingly larger FPGA devices, it is tempting to continue using conventional code generation techniques to construct hardware designs from high-level languages. However, in this paper we make a case against the application of conventional techniques to hardware design in favor of a new code generation approach that enables the use of heavily customized, parameterizable modules. This approach moves a portion of the generation functionality into tiles, which handle the negotiation of a module's parameters and subsequently the instantiation of the parameterized module. Furthermore, the tiles are automatically discovered at run-time and dynamically loaded into the design generator, which allows the system to be readily extended. This approach has been implemented in a collaborative, problem-solving design environment for reconfigurable computing. It is shown --- with respect to latency, throughput, and size --- that the proposed approach to hardware design generation is significantly more efficient than the conventional code generation techniques.