Ying He

Direct sunlight and reflections from buildings and ground surfaces create multi-source highlights in high-density built environments, potentially affecting outdoor visual safety and spatial use. This integrative review synthesizes daytime outdoor glare research in terms of physical characteristics, observer effects, and assessment methods. Solar movement, surface reflection, spatial obstruction, and observer movement jointly alter the intensity, direction, scale, and number of bright regions. Outdoor glare is therefore high-luminance, multi-source, non-uniform, and time-varying, occurring as concentrated, continuous-area, and discrete-patch highlights. Evidence indicates that outdoor glare causes visual discomfort, impairs target recognition, and may induce immediate behavioral adjustments. However, studies focus mainly on static viewpoints, short-term perception, and driving tasks, with limited direct observation of spatial-use outcomes such as dwell time, detouring, and location choice. Current assessments identify potential exposure through geometric-path analysis or quantify glare stimuli using established indices and extended models. Some metrics support relative comparisons within specific settings but cannot simultaneously characterize spatial reachability, stimulus intensity, dynamic exposure, and observer responses. Future research should develop hierarchical, type-specific dynamic assessment methods based on glare source, spatial scale, and visual task to inform building-envelope design, material selection, and outdoor glare-risk control.

With ongoing urbanization, driving environments have become increasingly complex, substantially increasing the volume of information drivers must process. To explore the impact of environmental complexity on driving safety, this study addresses the limitations of previous research in quantitatively analyzing multidimensional urban environmental factors. It introduces the Driver Sky View Index (DSVI), a visual field–based metric for quantifying environmental complexity. A method for extracting the sky view ratio was developed by integrating 3D street scene modeling with semantic segmentation, enabling a nonlinear mapping between DSVI and environmental complexity. A virtual reality simulation was employed to model nine scenarios across three road segments characterized by varying DSVI levels. Eye-tracking technology and a synchronized driving behavior recording system were used to capture visual and operational responses from 24 participants. The entropy weight–rank sum ratio (EW-RSR) composite algorithm was then applied to quantify the impact of DSVI thresholds on driving safety. The results indicate that DSVI significantly affects both driver behavior and visual characteristics, effectively reflecting how environmental complexity influences driving performance. Moreover, DSVI demonstrates a strong linear correlation with driving load (R² = 0.641, p < 0.05). Notably, when the DSVI value ranges from 0.241 to 0.397, a marked improvement in driving safety is observed. As an innovative quantitative indicator, DSVI not only facilitates the evaluation and optimization of urban traffic environments but also provides a valuable reference for enhancing driving comfort and safety.

Lightbox luminance and colour play an important role in improving the legibility of metro directional signs. However, there are currently no relevant design and technical standards. This study examined the effect of lightbox colour and luminance on wayfinding sign legibility. First, a set of levels for the background luminance of the lightboxes was proposed. Second, based on the perceived brightness magnitude, test points and luminance thresholds were determined under different background luminance levels. Visual acuity tests were then performed using a white Landolt C with different luminance values on different sign backboard colours under varying background luminance levels. The results indicate that both lightbox colour and Landolt C luminance impacted legibility, with the latter exhibiting a greater effect. Wayfinding sign legibility with the same luminance increased significantly with higher background luminance. Moreover, legibility differed substantially between achromatic and coloured lightboxes: the average acuity of coloured lightboxes was lower at low background luminance, whereas the opposite was true at high background luminance. Accordingly, minimum luminance thresholds were proposed according to lightbox colour and background luminance based on an average acuity of 95%. These findings provide an important reference for luminance control of different coloured lightboxes in metro stations.

As a major contributor to global energy consumption and carbon emissions, the building sector plays a pivotal role in achieving carbon peaking and neutrality targets. This study systematically reviews the evolution of research on building stock energy conservation and emission reduction (BSECER) from 1992 to 2025, which is based on a comprehensive bibliometric analysis of 2643 publications. The analysis highlights the research contributions of countries, institutions, and scholars in the BSECER field, reveals patterns in collaborative networks, and identifies the development and shifting focus of research topics over time. The findings indicate that current BSECER research centers around four main areas: behavioral efficiency optimization, full life cycle carbon management, urban system transformation, and the integration of intelligent technologies, which collectively form a multiscale emission reduction framework from individual behavior to large-scale systems. Building on these insights, this study outlines five key future research directions: advancing comprehensive carbon neutrality technologies, accelerating the engineering application of intelligent technologies, developing innovative multi-scenario policy simulation tools, overcoming integration challenges in renewable energy systems, and establishing an interdisciplinary platform that links health, behavior, and energy conservation.