###### Analysis of crack propagation in a “pull-out” test

compression test performed on the same samples. Photograph from these tests are shown in Fig. 4 . On the left side, the displacement sensor is visible, which measures the vertical deformations, and on the right side, there is the extensometer that measures the horizontal deformations. It is mounted on steel plates glued to the opposite sides of samples. Figure 4 Compression with extensometer test. The Young modulus was calculated from the below equation: (3.1) E = h ⋅ κ A $$E=\frac{h\cdot \kappa }{A}$$ where, h is the

###### Method for Assessment of Changes in the Width of Cracks in Cement Composites with Use of Computer Image Processing and Analysis

scale-invariant keypoints, International Journal of Computer Vision, 2004, 60 (2), 91-110. [5] KANELLOPOULOS A., QURESHI T.S., AL-TABBAA A., Glass encapsulated minerals for self-healing in cement based composites, Construction and Building Materials, 2015, 98, 780-791. [6] PAWLIK P., MIKRUT S., Wyszukiwanie punktów charakterystycznych na potrzeby zdjęć lotniczych, Automatyka, 2006, 10 (3), 407-411. [7] SZELĄG M., FIC S., Analiza rozwoju spękań klastrowych w zaczynie cementowym modyfikowanym mikrokrzemionką, Budownictwo i

###### A note on the differences between Drucker-Prager and Mohr-Coulomb shear strength criteria

equivalent measure of principal stress ratio. Introducing equations (8) - (10) into the definitions of invariants the following relations are obtained: I 1 = 3 p − a q , $${{I}_{1}}=3p-aq,$$ (12) J 2 = q 2 3 ( a 2 + 3 ) , $${{J}_{2}}=\frac{{{q}^{2}}}{3}\left( {{a}^{2}}+3 \right),$$ (13) J 3 = 2 a 27 q 3 ( − a 3 + 9 ) . $$ {{J}_{3}}=\frac{2a}{27}{{q}^{3}}\left( -{{a}^{3}}+9 \right).$$ (14) Finally the Lode angle θ ϵ 〈-π/6, π/6〉 is introduced by

###### Urban area change visualization and analysis using high density spatial data from time series aerial images

land or object surfaces are called point clouds. Point clouds of land surfaces can be obtained from LiDAR (light detection and ranging), SAR (synthetic aperture radar) or photogrammetry from stereo or multiview images. The point space of aerial and terrestrial LiDAR depends on the technical specification of the instrument ( Ghuffar et al., 2013 ). LiDAR has a sufficient level of measurement accuracy but requires expensive procedures. Thus, LiDAR cannot be applied to every measurement task. SAR is applied by satellite and measures the earth’s surface at particular (1