We study surface subgroups of groups acting simply transitively on vertex sets of certain hyperbolic triangular buildings. The study is motivated by Gromov’s famous surface subgroup question: Does every oneended hyperbolic group contain a subgroup which is isomorphic to the fundamental group of a closed surface of genus at least 2? In [10] and [3] the authors constructed and classified all grou...

Recent work has produced a theory for tropical convective available potential energy (CAPE) that highlights the Clausius-Clapeyron (CC) scaling of the atmosphere’s saturation deficit as a driver of increases in CAPE with warming. Here we test this so-called “zero-buoyancy” theory for CAPE by modulating the saturation deficit of cloud-resolving simulations of radiative-convective equilibrium in ...

Airborne laser scanning has become an arch technology and which is now widely accepted for 3D data collection. These 3D points represent the terrain surface as well as objects on top of the terrain surface. Airborne LIDAR systems are able to record data through multiple pulses which make the data very accurate. LIDAR data is a relatively new technology for obtaining Digital Surface Models (DSM)...

The paper applies a computer-based method involving stochastic search, multi-criteria optimization and color filtering to investigate the tradeoff between the life-cycle profitability of highrise commercial office buildings and their load-path safety against progressive collapse under abnormal loading. The study was motivated by the progressive-collapse failure of the twin towers of the World T...

In urban GIS and management, Digital surface model (DSM) can be used for generating object models. The preliminary step is to segment the interesting areas. In this paper, we present an integrated method of building extraction using transform from DSM to normal angles and watershed segmentation to the gradient of DSM. To remove the effect of the terrain shape to building detection, we firstly d...

An approach was developed for updating the buildings of an existing vector database from high resolution space images by using spectral values, Digital Elevation Models (DEM) and model-based extraction techniques. First, the building areas are detected using image classification and normalized Digital Surface Model (nDSM). Those areas other than the buildings are excluded from further processin...

The classification of land use, degree of development, and the location of major features, such as buildings and expanses of vegetation are of considerable interest to planning bodies, relief agencies, and the military. Landscape characteristics are under continuous modification, especially in urban and suburban areas, and therefore the maps of these areas need regular updating. Derived databas...

Significant crustal movements were caused by the 2011 Tohoku, Japan Earthquake. A method for capturing the surface movements from TerraSAR-X intensity images is proposed in this study. First, the buildings were extracted from the preand post-event images using a segmentation approach. Then, the unchanged buildings were detected by matching the buildings in the preand post-event images at simila...

We present a system for modeling buildings from a single correlation-based Digital Elevation Model (DEM). The model is constructed in two stages. The first stage segments the DEM into planar surface patches that describe the building. The second stage generates the final polygonal model of the building using weak geometric constraints. We use robust estimation methods at different stages of our...