分类：Publications

Abstract: An understanding of guidance, which means guiding attention, and constancy, meaning that an area can be perceived for what it is despite environmental changes, of the visual variables related to three-dimensional (3D) symbols is essential to ensure rapid and consistent human perception in 3D visualization. Previous studies have focused on the guidance and constancy of visual variables related to two-dimensional (2D) symbols, but these aspects are not well documented for 3D symbols. In this study, we used eye tracking to analyze the visual guidance from shapes, hues and sizes, and the visual constancy that is related to the shape, color saturation and size of 3D symbols in different locations. Thirty-six subjects (24 females and 12 males) participated in the study. The results indicate that hue and shape provide a high level of visual guidance, whereas guidance from size, a variable that predominantly guides attention in 2D visualization, is much more limited in 3D visualization. Additionally, constancy of shape and saturation are perceived with relatively high accuracy, whereas constancy of size is perceived with only low accuracy. These first empirical studies are intended to pave the way for a more comprehensive user understanding of 3D visualization design.

Cite this paper:

Liu, B.; Dong, W.; Meng, L. Using Eye Tracking to Explore the Guidance and Constancy of Visual Variables in 3D Visualization. ISPRS Int. J. Geo-Inf. 2017, 6, 274. doi: 10.3390/ijgi6090274

Abstract: LiDAR has been an effective technology for acquiring urban land cover data in recent decades. Previous studies indicate that geometric features have a strong impact on land cover classification. Here, we analyzed an urban LiDAR dataset to explore the optimal feature subset from 25 geometric features incorporating 25 scales under 6 definitions for urban land cover classification. We performed a feature selection strategy to remove irrelevant or redundant features based on the correlation coefficient between features and classification accuracy of each features. The neighborhood scales were divided into small (0.5–1.5 m), medium (1.5–6 m) and large (>6 m) scale. Combining features with lower correlation coefficient and better classification performance would improve classification accuracy. The feature depicting homogeneity or heterogeneity of points would be calculated at a small scale, and the features to smooth points at a medium scale and the features of height different at large scale. As to the neighborhood definition, cuboid and cylinder were recommended. This study can guide the selection of optimal geometric features with adaptive neighborhood scale for urban land cover classification.

Cite this paper: Dong, W., Lan, J., Liang, S., Yao, W. and Zhan, Z. 2017. Selection of LiDAR geometric features with adaptive neighborhood size for urban land cover classification. International Journal of Applied Earth Observation and Geoinformation, 60, 99-110. DOI: 10.1016/j.jag.2017.04.003

Abstract: 3D representations in applications that provide self-localization and orientation in wayfinding have become increasingly popular in recent years because of technical advances in the field. However, human factors have been largely ignored while designing 3D representations in support of pedestrian navigation. This exploratory study aims to explore gender effects on using 3D maps for spatial orientation. We designed a 3D map that combines salient 3D landmarks and 2D layouts, and evaluated gender differences in their performance during direction-pointing tasks by administrating an eye tracking experiment. The results indicate there was no significant overall gender difference on performance and visual attention. However, we observed that males using the 3D map paid more attention to landmarks in the environment and performed better than when using the conventional 2D map, whereas female performance did not show any significant difference between the two types of map usage. We also observed contrary gender differences in visual attention on landmarks between the 3D and 2D maps. While males fixated longer on landmarks than females when using the 3D map, females paid more visual attention to landmarks than males when using the 2D map. In addition, verbal protocols showed that males had more confidence while make decisions. These empirical results can be helpful in the design of map-based wayfinding enhancement tools.

Cite this paper: Liao H, Dong W. An Exploratory Study Investigating Gender Effects on Using 3D Maps for Spatial Orientation in Wayfinding. ISPRS International Journal of Geo-Information. 2017; 6(3):60. DOI: http://dx.doi.org/10.3390/ijgi6030060

 

Abstract: Nowadays, studies of factors influencing geographical spatial orientation ability mainly concentrate on gender whereas relationships of field cognitive style and spatial terminology with spatial orientation ability have rarely been studied. This study used eye tracking technology to explore the influences of the three individual variables on spatial orientation ability. 86 people participated in the experiments with an average age of 21 (SD=2.67). 继续阅读“Study on the Influence of Field Cognitive Style, Gender and Spatial Terminology on Geographical Spatial Orientation Ability: based on Experiments in Virtual Space”

Abstract: Despite the now-ubiquitous two-dimensional (2D) maps, photorealistic three-dimensional (3D) representations of cities (e.g., Google Earth) have gained much attention by scientists and public users as another option. However, there is no consistent evidence on the influences of 3D photorealism on pedestrian navigation. Whether 3D photorealism can communicate cartographic information for navigation with higher effectiveness and efficiency and lower cognitive workload compared to the traditional symbolic 2D maps remains unknown. 继续阅读“Eye tracking to explore the impacts of photorealistic 3d representations in pedestrian navigation performance”

Abstract: Despite the now-ubiquitous two-dimensional (2D) electronic maps, three-dimensional (3D) globe viewers, or 3D geo-browsers such as Google Earth and NASA World Wind have gained much attention. However, the effect of such interactive 3D geo-browsers on spatial knowledge acquisition and decision making is not well known. This study aims to explore the potential benefits of using interactive 3D geo-browsers in three processes of pedestrian navigation (self-localization, spatial knowledge acquisition, and decision making) in digital environments. 继续阅读“Exploring Differences of Visual Attention in Pedestrian Navigation when using 2D Maps and 3D Geo-browsers”

Abstract: Current studies of map symbols mainly concentrate on the basic visual variables such as color, shape and size, which are commonly used in two dimensional maps. Recent technical advances and the ubiquitous use of smart devices have made three- dimensional (3D) maps (e.g., Google Maps and AutoNavi) increasingly popular. However, 3D visual variables, such as field of view (FOV) and viewing angle (VA) which play fundamental roles in visual information processing of 3D maps and spatial scenes, have been rarely investigated. 继续阅读“The Influence of FOV and Viewing Angle on the Visual Information Processing of 3D Maps”

Abstract: The morbidity and mortality of hand, foot and mouth disease (HFMD) are increasing in Beijing, China. Previous studies have indicated an association between incidents of HFMD and weather factors. However, the seasonal influence of these factors on the disease is not yet understood, and their relationship with the enterovirus 71 (EV71) and Coxsackie virus A16 (CV-A16) viruses are not well documented. We analysed 84,502 HFMD cases from 2008 to 2011 in Beijing to explore the seasonal influence of weather factors (average temperature [AT], average relative humidity [ARH], total precipitation [TP] and average wind speed [AWS]) on incidents of HFMD by using a geographically weighted regression (GWR) model. 继续阅读“The Effects of Weather Factors on Hand, Foot and Mouth Disease in Beijing”

Abstract: Motivated by growing heat-related morbidity and mortality in a warming climate, this paper assesses global heat health risk in order to understand the challenges to sustainability in the 21st century, using four Representative Concentration Pathways (RCPs) of the HadGEM2-ES climate model and five Shared Socio-Economic Pathways (SSPs). Factors influencing global heat health risk were reviewed and risks were estimated based on heat hazard and socio-economic vulnerability. Hazard, vulnerability, risk and in particular, populations at different risk levels, were analyzed quantitatively at both global and regional scales. 继续阅读“New climate and socio-economic scenarios for assessing global human health challenges due to heat risk”

Abstract: This paper presents a new perspective of national power—sustainable national power (SNP)—emphasizing both the traditional comprehensive national power (CNP) and social and environmental sustainability. We propose a measurement to quantify the SNP based on the measurement of comprehensive national power and a sustainable adjusted index. In addition, density-equalizing maps are adopted to visualize the sustainable national power of countries in order to gain a better understanding for its current state and future development from a cartographic perspective.

继续阅读“Towards Measuring and Visualizing Sustainable National Power—A Case Study of China and Neighboring Countries”