Conventional two dimensional (2D) maps and DEM's are insufficient to represent geographic information in urban space comprising high-rise buildings and underground structures. There is a pressing need for a model of three dimensional (3D) representation of urban space, that is, a Digital Urban Space Model (DUSM) . However existing solid modelling techniques cannot be directly applied to the 3D representation due to several problems such as the inefficiency in building and updating 3D spatial database. Based on the boundary representation (BR) model, the authors propose a Surface Representation (SR) model which can greatly improve the efficiency in building and updating 3D spatial database. Through an example of the 3D representation of urban space, it is demonstrated that the SR model can be successfully applied.
The analysis of human movement has its origin in the age of Aristotle; Hippocrates used it in prescribing physical exercise for cure of patients impairments and disabilities. Now, functional anatomy, neurology and physiology of human movement are highly developed in rehabilitation science, and information given by 3D digital stereo photogrammetry, kinesiology and especially biomechanics (application of principles of dynamics to analyze human movement) is expected to become more important. This paper describes a new approach to analyze human movement using the simple 3D photogrammetric analyzer system “BIRDMAN” and the trajectories of flickering LEDs, (lightemitting diodes) attached to measurement points on major joints. All are controlled by an IC clock, (turned on and off once each 0.1 second, with two non-metric synchronized cameras. This study increased the sampling rate by 2.5 times over that using the inter-barometer (frequency 0.25 second) used in our previous study. Thus, the details of human movement for each second are better presented. The test data are obtained from the walking movement of a person who has been well trained for dancing for four years and that of another person who has not been trained. Using 3D photogrammetrically analyzed digital data, the displacement and change of metabolic energy and torque of the person's major joints are presented as biomechanical analysis of human walking. The results are as follows: 1. the displacements of the trained person's elbows, shoulders and hips are comparatively smoother and more rhythmic, in the 3D space, than those of the untrained person. 2. the change of metabolic energy of the hip (estimated from the hip displacement) of the trained person is comparatively smaller and more efficient than that of the untrained person. 3. the change of torque around shoulder joints of the trained person is comparatively smaller and more efficient than that of the untrained person. As a result of this study it can be said that the 3D photogrammetrc algorithm and analysis using LEDs, as developed in this study, are useful for biomechanical and physiological analysis of human movement.