Abstract: 2-hydroxy-5-[2-(4-(trifluoromethylphenyl)ethylamino)]benzoic acid crystal forms and a preparation method therefor are proposed. Crystal form I is a monoclinic crystal system, which has a Pc space group and can be obtained by slow cooling, evaporating the solvent at a constant temperature, evaporating the solvent at an increased temperature, or adding an anti-solvent. Crystal form II is a triclinic crystal system, which has a P1 space group and can be obtained by rapid cooling or freeze-drying. According to the method, the process is simple, costs are low, and the yield exceeds 90%; and the crystal forms of the crystal forms I and II have high purity, the crystal shapes thereof are intact, and have excellent fluidity, facilitating preparation, particularly the preparation of a pharmaceutical preparation for preventing and/or treating degenerative diseases of the central nervous system. Furthermore, the two crystal forms have a better apparent solubility than that of raw materials.

Abstract: Provided is a method of compressing an occupancy map of a three-dimensional (3D) point cloud, and more specifically, a method of compressing an occupancy map of a point cloud in which an occupancy map image of a point cloud existing in a 3D space is compressed based on a compression quality or a patch-by-patch inspection method of the occupancy map image so that compression distortion is minimized when reconstructing the compressed occupancy map image so as to remarkably improve the quality of a reconstructed occupancy map image.

Abstract: A CMOS image sensor with improved sensitivity includes a main pixel array region of an active pixel array region formed on a semiconductor substrate. A passivation layer is formed over the sensor, and it is at least partially removed from the main pixel array region, such that incident light being detected by the main pixel array does not pass through the passivation layer. Optical absorption and refraction caused by the material of the passivation layer are eliminated, resulting in an image sensor with improved optical sensitivity.