Abstract: The present disclosure relates to a dehydration catalyst, a method for preparing the same, and a method for preparing an alkene using the same. More particularly, the present invention relates to a dehydration catalyst that is mixed-phase alumina including 1 to 18% by weight of alpha-alumina, 65 to 95% by weight of theta-alumina, and 4 to 34% by weight of delta-alumina, a method for preparing the dehydration catalyst, and a method for preparing an alkene using the dehydration catalyst.

Abstract: In an embodiment an apparatus includes a processor configured to generate a feature extraction module using a dataset in which an attribute for each object is defined, receive an image obtained by a camera, extract an attribute of an object of interest from the image using the learned feature extraction module, identify an object re-identification candidate group based on the extracted attribute of the object of interest and re-identify the object of interest based on the identified object re-identification candidate group.

Abstract: A compact optical pickup in which the optical elements are mounted on an optic holder driven as a unitary structure. The pickup includes the optic holder having a vertical hole at one end through which a laser beam passes, a horizontal opening which communicates with the vertical hole, an objective lens installed at the top of the vertical hole, a reflection mirror at the juncture of the vertical hole and horizontal opening, and a hybrid optical unit consisting of optical elements positioned at the other end of the optic holder to scan the reflection mirror with the laser beam via the horizontal opening and detect the laser beam reflected from the disk. The pickup further includes a support for suspending the optic holder from a base, simultaneously keeping balance between the objective lens at the one end of the optic holder and the hybrid optical unit at the other, and elastically supporting the optic holder, and a driver for driving the optic holder vertically and horizontally.