# Sustainable Planning and Design of Ocean City Spatial Forms Based on Space Syntax
## 3 The PAD of an OC Based on Space Syntax (SS)  
### Correlation Analysis of SS  
#### 3.1.1 Meaning of SS  
Over the past forty years, SS research methods have been constantly improved and refined, and a well-established theoretical system has gradually been formed. Founded on spatial ontology, the basic idea of SS is to divide large-scale space and mathematically abstract and model it to explore the connection between spatial ontology and other non-spatial elements. The scope of SS research involves a large number of aspects, such as urban planning, urban design, architecture, and spatiography, gradually forming an integrated discipline with multiple ways of thinking [20].  
SS is a theory and method that investigates physical space and the spatial composition of human cognition by quantitatively describing the spatial structure of a human settlement [21]. It highlights the research on the correlation between \"space\" as an independent element and architecture, society, and human cognition. According to SS, the OC space system consists of two parts: closed space and free space. Closed space generally refers to buildings, while free space is a place separated by objects where people can move around at will. In free space, any point can reach other points in space and demonstrate continuity; thus, it is also called open space. The space system created by people is produced in social development. Upon the completion of the space system, it has social attributes; these social attributes of OCs or architectural spaces are not determined artificially and subjectively by attaching functional labels.  
The SS method is employed to understand and utilize the effect of a spatial configuration in urban systems or complex buildings. It can be seamlessly linked to GIS network analysis, superposition analysis, data connection, and other functions, and has great superiority regarding data modification, sorting, and mapping. ENVI focuses on image processing, such as correction, stitching, index calculation, and classification; in contrast, ArcGIS emphasizes the construction, analysis, and calculation of geographical information to provide statistical and regional analyses based on geographic space, and is more suited for the analysis and processing functions of spatial information.  
According to the new space theory, which states that space is a part of social life, human settlements, such as the layout of OCs or architectural spaces, will influence society, the economy, and culture and innovatively show the social logic of spatial structure. SS is different from traditional research on space theory in that SS takes space as the starting point to dissect the relationship between the OC and social and cognitive areas (e.g., architectural space). The general research relations of SS are shown in Figure 1.  
The division of spatial scale and the segmentation of space is an important foundation of SS research.  
Division of spatial scale: The division of spatial scale is the basis of SS and also the primary step in SS research. SS divides space into two space scales: large and small. The division criterion is whether individuals in a space can fully perceive the space. If so, then the space is a small-scale space; if not, or if they can only perceive a part of the space, then the space is a large-scale space [22].  
Segmentation of space: SS assumes that it is difficult for individuals to feel the entirety of a large-scale space. In studies on large-scale spaces, such as cities, SS divides them into three types of small-scale space. Axial segmentation refers to the farthest distance that can be seen from a given point in space. Convex space segmentation refers to the ability of any point in space to see another point in space; that is, the space can be fully perceived. FOV (field of view) segmentation refers to the scope of horizontal space that can be perceived at a given point. At present, axial segmentation is most widely used in research utilizing SS theory.