Ted Nguyen

Virtual Reality (VR) is increasingly used in spatial cognition research, as it offers high experimental control in naturalistic multimodal environments, which is hard to achieve in real-world settings. Although recent technological advances offer a high level of photorealism, locomotion in VR is still restricted because people might not perceive their self-motion as they would in the real world. This might be related to the inability to use embodied spatial orientation processes, which support… Show more

Virtual Reality (VR) is increasingly used in spatial cognition research, as it offers high experimental control in naturalistic multimodal environments, which is hard to achieve in real-world settings. Although recent technological advances offer a high level of photorealism, locomotion in VR is still restricted because people might not perceive their self-motion as they would in the real world. This might be related to the inability to use embodied spatial orientation processes, which support automatic and obligatory updating of our spatial awareness. Previous research has identified the roles reference frames play in retaining spatial orientation. Here, we propose using visually overlaid rectangular boxes, simulating reference frames in VR, to provide users with a better insight into spatial direction in landmark-free virtual environments. The current mixedmethod study investigated how different variations of the visually simulated reference frames might support people in a navigational search task. Performance results showed that the existence of a simulated reference frame yields significant effects on participants completion time and travel distance. Though a simulated CAVE translating with the navigator (one of the simulated reference frames) did not provide significant benefits, the simulated room (another simulated reference frame depicting a rest frame) significantly boosted user performance in the task as well as improved participants preference in the post-experiment evaluation. Results suggest that adding a visually simulated reference frame to VR applications might be a cost-effective solution to the spatial disorientation problem in VR. Show less

Head-Mounted Displays (HMDs) provide immersive experiences for virtual reality. However, their field of view (FOV) is still relatively small compared to the human eye, which adding sparse peripheral displays (SPDs) could address. We designed a new SPD, SparseLightVR2, which increases the HMD's FOV to 180° horizontally. We evaluated SparseLightVR2 with a study (N=29) by comparing three conditions: 1) no SPD, where the peripheral display (PD) was inactive; 2) extended SPD, where the PD provided… Show more

Head-Mounted Displays (HMDs) provide immersive experiences for virtual reality. However, their field of view (FOV) is still relatively small compared to the human eye, which adding sparse peripheral displays (SPDs) could address. We designed a new SPD, SparseLightVR2, which increases the HMD's FOV to 180° horizontally. We evaluated SparseLightVR2 with a study (N=29) by comparing three conditions: 1) no SPD, where the peripheral display (PD) was inactive; 2) extended SPD, where the PD provided visual cues consistent with and extending the HMD's main screen; and 3) counter-vection SPD, where the PD's visuals were flipped horizontally during VR travel to provide optic flow in the opposite direction of the travel. The participants experienced passive motion on a linear path and reported introspective measures such as sensation of self-motion. Results showed, compared to no SPD, both extended and counter-vection SPDs provided a more natural experience of motion, while extended SPD also enhanced vection intensity and believability of movement. Yet, visually induced motion sickness (VIMS) was not affected by display condition. To investigate the reason behind these non-significant results, we conducted a follow-up study and had users increase peripheral counter-vection visuals on the central HMD screen until they nulled out vection. Our results suggest extending HMDs through SPDs enhanced vection, naturalness, and believability of movement without enhancing VIMS, but reversed SPD motion cues might not be strong enough to reduce vection and VIMS. Show less

Despite recent advances in virtual reality, locomotion in a virtual environment is still restricted because of spatial disorientation. Previous research has shown the benefits of reference frames in maintaining spatial orientation. Here, we propose using a visually simulated reference frame in virtual reality to provide users with a better sense of direction in landmark-free virtual environments. Visually overlaid rectangular frames simulate different variations of frames of reference. We… Show more

Despite recent advances in virtual reality, locomotion in a virtual environment is still restricted because of spatial disorientation. Previous research has shown the benefits of reference frames in maintaining spatial orientation. Here, we propose using a visually simulated reference frame in virtual reality to provide users with a better sense of direction in landmark-free virtual environments. Visually overlaid rectangular frames simulate different variations of frames of reference. We investigated how two different types of visually simulated reference frames might benefit in a navigational search task through a mixed-method study. Results showed that the presence of a reference frame significantly affects participants' performance in a navigational search task. Though the egocentric frame of reference (simulated CAVE) that translates with the observer did not significantly help, an allocentric frame of reference (a simulated stationary room) significantly improved user performance both in navigational search time and overall travel distance. Our study suggests that adding a variation of the reference frame to virtual reality applications might be a cost-effective solution to enable more effective locomotion in virtual reality. Show less

In modern world, children need to get familiar with interactive toys to quickly improve their learning and imagination. Our approach is to add augmented information and interaction to common toys on the surface containing them, which is called Smart Playground. Popular methods use three color channels and local features to recognize objects. However, toys of children usually have various pictures with different colors drawn on many small components. Therefore depth data is useful in this case… Show more

In modern world, children need to get familiar with interactive toys to quickly improve their learning and imagination. Our approach is to add augmented information and interaction to common toys on the surface containing them, which is called Smart Playground. Popular methods use three color channels and local features to recognize objects. However, toys of children usually have various pictures with different colors drawn on many small components. Therefore depth data is useful in this case. Each toy usually have unique shape that is distinguishable from others. In this paper, we use an RGB-D sensor to collect information about both color and shape of objects. To learn the training set of toys, an approach of convolutional neural network is used to represent data (both color and depth) by high-level feature vectors. Using the combined results, the accuracy of 3D recognition is more than 90 %. Show less

Young children need their parents' love and care but their parents are not always available to tell them stories. This motivates our proposal of a Smart Teddy Bear, a vision-based story teller, to assist young children in their social-emotional growth. When a young child wants to listen to a story, he or she simply opens any page in that book before a Smart Teddy Bear and the system automatically recognizes which book is of interest and plays the corresponding audio story. Our proposed system… Show more

Young children need their parents' love and care but their parents are not always available to tell them stories. This motivates our proposal of a Smart Teddy Bear, a vision-based story teller, to assist young children in their social-emotional growth. When a young child wants to listen to a story, he or she simply opens any page in that book before a Smart Teddy Bear and the system automatically recognizes which book is of interest and plays the corresponding audio story. Our proposed system is based on the Bag-of-Words model. We propose to eliminate too small visual features and to downscale an image up to 1/16 of its original size to remove up to 70% of unnecessary visual features. Furthermore we ensemble results of multiple lightweight SVM classifiers to boost the overall accuracy. Experimental results show that our system achieves the accuracy of 99.33% with 40 books containing 1369 different pages. We propose the Smart Teddy Bears help children enjoy audio books in a new exciting way through attractive interactions with their lovely toys. Show less

This study shows how brain sensing can offer insight to the evaluation of human spatial orientation in virtual reality (VR) and establish a role for electroencephalogram (EEG) in virtual navigation. Research suggests that the evaluation of spatial orientation in VR benefits by goingbeyond performance measures or questionnaires to measurements of the user’s cognitive state. While EEG has emerged as a practical brain sensing technology in cognitive research, spatial orientation tasks often rely… Show more

This study shows how brain sensing can offer insight to the evaluation of human spatial orientation in virtual reality (VR) and establish a role for electroencephalogram (EEG) in virtual navigation. Research suggests that the evaluation of spatial orientation in VR benefits by goingbeyond performance measures or questionnaires to measurements of the user’s cognitive state. While EEG has emerged as a practical brain sensing technology in cognitive research, spatial orientation tasks often rely on multiple factors (e.g., reference frame used, ability to update simulated rotation, and/or left-right confusion) which may be inaccessible to this measurement. EEG has been shown to correlate with human spatial orientation in previous research. In this paper, we use convolutional neural network (CNN), an advanced technique in machine learning, to train a detection model that can identify moments in which VR users experienced some increase in spatial orientation demands in real-time. Our results demonstrate that we can indeed use machine learning technique to detect such cognitive state of increasing spatial orientation demands in virtual reality research with 96% accurate on average. Show less