Abstract: An apparatus, for measuring overlay, includes: a height difference detection optical system detecting a height difference between a first overlay mark and a second overlay mark; an illumination optical system irradiating the overlay mark with illumination light; a main beam splitter splitting a reflected light from the overlay mark into a first beam and a second beam; a first detector receiving the first beam and generating a first overlay mark image in which the first overlay mark is displayed; a second detector receiving the second beam and generating a second overlay mark image in which the second overlay mark is displayed; an imaging optical system allowing the first beam to be imaged on the first detector; and a telecentric imaging optical system adjusting a length of an optical path of the second beam to allow the second beam to be imaged on the second detector.

Abstract: A memory device determines an operation mode based on an external voltage. The memory device includes a cell array including a plurality of memory cells; and a mode selector that detects a level of at least one voltage signal externally provided and selects any one of a plurality of operation modes corresponding to a plurality of standards according to a result of detecting the level of the at least one voltage signal. The memory device further includes a mode controller that, in response to a mode selecting signal from the mode selector, outputs setting information for setting the memory device to communicate with a memory controller via an interface according to a selected standard from among the plurality of standards; and a calibrating circuit that generates a control code for controlling circuit blocks in the memory device according to the setting information.

Abstract: Provided are an emergency stop apparatus including a switch unit installed in a work space, electrically connected to a facility, and operable by pulling and a wire which is disposed in the work space so that tension is applied and of which at least one side is detachably mounted on the switch unit and an emergency stop method for quickly stopping the facility at a desired position within the work space in a manner of pulling or pushing the wire.

Abstract: Provided are a novel polyketone polymerization catalyst and a method of preparing a ligand, which can reduce production costs and can enable commercial mass synthesis by using ((2,2-dimethyl-1,3-dioxane-5,5-diyl)bis(methylene))bis(bis(2-methoxyphenyl)phosphine) as a ligand constituting the polykeytone polymerization catalyst, the ligand having a simple structure and a small molecular weight while having high activity.

Abstract: A memory device determines an operation mode based on an external voltage. The memory device includes a cell array including a plurality of memory cells; and a mode selector that detects a level of at least one voltage signal externally provided and selects any one of a plurality of operation modes corresponding to a plurality of standards according to a result of detecting the level of the at least one voltage signal. The memory device further includes a mode controller that, in response to a mode selecting signal from the mode selector, outputs setting information for setting the memory device to communicate with a memory controller via an interface according to a selected standard from among the plurality of standards; and a calibrating circuit that generates a control code for controlling circuit blocks in the memory device according to the setting information.

Abstract: Provided are an emergency stop apparatus including a switch unit installed in a work space, electrically connected to a facility, and operable by pulling and a wire which is disposed in the work space so that tension is applied and of which at least one side is detachably mounted on the switch unit and an emergency stop method for quickly stopping the facility at a desired position within the work space in a manner of pulling or pushing the wire.

Abstract: Provided are a novel polyketone polymerization catalyst and a method of preparing a ligand, which can reduce production costs and can enable commercial mass synthesis by using ((2,2-dimethyl-1,3-dioxane-5,5-diyl)bis(methylene))bis(bis(2-methoxyphenyl)phosphine) as a ligand constituting the polykeytone polymerization catalyst, the ligand having a simple structure and a small molecular weight while having high activity.