High-fidelity vibration actuators in recent mobile phones allow designers to crowdsource user evaluation of vibrotactile (VT) Tactons. Yet, little work has examined whether online crowdsourcing platforms can provide comparable results to lab studies. To address this question, we conducted two studies with iOS devices in the lab and crowdsourced settings. In Study I, 40 users provided pairwise similarity ratings for 12 VT Tactons that varied in their parameters (e.g., duration). In Study II, 40 new users rated pairwise similarities for 14 Tactons representing different metaphors (e.g., heartbeat). They also rated the Tactons’ match to the metaphors. In both studies, the resulting similarities and perceptual spaces strongly correlated in the lab and crowdsourced settings. Furthermore, 60% of the metaphor ratings were statistically equivalent in the two settings. We discuss the results and outline directions for future work on haptic crowdsourcing.

The main objective of this study is long-term monitoring of surface sediment on tidal flats using optical remote sensing. Tidal flat reflectance is sensitive to conditions that constantly change and cause variation of interstitial water contents along with exposure time, remnant water, etc. It is difficult to retrieve sediment grain size from optical reflectance alone without correcting the tidal condition effects. In this study, the tidal flat surface reflectance model according to grain size is proposed by two-step PCA transformation to remove tidal effects. The proposed method showed a potential to classify sediment by grain size regardless of exposure time and tidal conditions. We applied the method to nine scenes of LANDSAT TM images acquired between 1988 and 2009. The preliminary results well demonstrated that the proposed approach is effective to monitor changes of grain size distribution at a large scale independent of tidal conditions. However, this method has a limitation particularly over the vegetated areas and sand shoals mainly because of strong reflection in the NIR channels compared with other areas. For the validation, this study requires further field survey to obtain more in-situ data.