When a viewer browses a web site, one presumably performs the task of seeking information from a sequence of scattered web pages to form a meaningful path. The aim of this study is to explore changes in the distribution of attention to banner advertisements as a viewer advances along a meaningful path and their effects on the advertisements. With aid of an instrument called eye-tracker, a labor...

In this paper, we describe two aspects of a study we conducted of faceted search in an online public access library catalog (OPAC). First, we describe how we used log data from a university OPAC to develop a set of grounded tasks. Then, we describe our use of eye-tracking in a controlled laboratory setting to examine user behaviors performing the grounded tasks. We discuss the challenges we enc...

This paper proposes a new approach named predictive control of redundant manipulators based on avoidance manipulability to achieve an on-line control of trajectory tracking and obstacle avoidance for redundant manipulators. In the trajectory tracking process, manipulator is required to keep a configuration with maximal avoidance manipulability in real time. Predictive control in this paper uses...

We propose a gaze-based indicator of students’ attention in a MOOC video lecture. We report the results from an eye-tracking study during a MOOC lecture. We define the gazebased indicator of students’ attention as “with-me-ness”. This answers a question from teachers’ perspective “how much are the students with me?” With-me-ness is defined at two levels: perceptual, following teacher’s deictic ...

Taking into account relationships between interacting objects can improve the understanding of the dynamic model governing their behaviors. Moreover, maintaining a belief about the ongoing activity while tracking allows online activity recognition and improves the tracking task. We investigate the use of Relational Dynamic Bayesian Networks to represent the relationships for the tasks of multi-...

This paper presents a vision-based method for tracking guitar fingerings played by guitar players from stereo cameras. We propose a novel framework for colored finger markers tracking by integrating a Bayesian classifier into particle filters, with the advantages of performing automatic track initialization and recovering from tracking failures in a dynamic background. ARTag (Augmented Reality ...

This paper presents a robust method for tracking the position and orientation of a head in videos. The proposed method can overcome occlusions and divergence problems. We introduce an online registration technique to detect and register feature point of the head while tracking. A set of point features is registered and updated for each reference pose serving a multi-view head detector. The onli...

This paper presents a method to evaluate online the performance of tracking algorithms in surveillance videos. We use a set of features to compute the confidence of trajectories and also the precision of tracking results. A global score is computed online based on these features and is used to estimate the performance of tracking algorithms. The method has been tested with two real video sequen...

We introduce a probabilistic framework for simultaneous tracking and reconstruction of 3D rigid objects using an RGB-D camera. The tracking problem is handled using a bag-of-pixels representation and a back-projection scheme. Surface and background appearance models are learned online, leading to robust tracking in the presence of heavy occlusion and outliers. In both our tracking and reconstru...

Dynamic overlay of 3D models onto 2D X-ray images has important applications in image guided interventions. In this paper, we present a novel catheter tracking for motion compensation in the Transcatheter Aortic Valve Implantation (TAVI). To address such challenges as catheter shape and appearance changes, occlusions, and distractions from cluttered backgrounds, we present an adaptive linear di...