We present a visualization system that computes amplitude spectrum slopes from street-level imagery and visualizes their variation, allowing users to perceive parametric density in urban canyons. The system provides a pipeline for spatial analysis via three-dimensional heatmap rendering. Giving street-view image samples as input, it extracts a sequence of spectral slopes, mapping these values back onto geographical coordinates using AMap (Gaode). In the visualization, the height and color of three-dimensional meshes jointly encode the slope values of the amplitude spectrum, which have been associated with visual perception and comfort in prior work. This system helps users quickly interpret how the slopes of amplitude spectra vary across streets at the city scale, providing an interpretable proxy to support exploratory assessment in urban analytics and design.

Sharing with others can play a vital role in helping to cope with stress and emotional burdens. Biofeedback systems have been growing in HCI as supportive of individual stress management; however, the potential of leveraging neurofeedback systems for embodied forms of interpersonal stress sharing remains unexplored. We present Minus × Minus=Plus, an interactive system that externalizes collective neural activity to create a shared affective space. The system allows two participants to visualize their stress in real time via Electroencephalography (EEG) and to jointly transform it through two forms of haptic interaction. The system was tested with 110 participants (55 pairs), and their experience of embodied stress sharing was evaluated. Results show that our system significantly promoted the sharing process, underscoring the central role of visual and haptic modalities. This work contributes empirical evidence and design insights for developing neurofeedback systems that foster interpersonal stress sharing and support mental health.