Abstract: A display test apparatus includes a measuring apparatus and a calculating device connected to the measuring apparatus. The measuring apparatus provides a sample pixel value to a first display device including a first display panel, measures a first color coordinate value of an image displayed by the first display panel in response to the sample pixel value. The calculating device generates a first parameter of the first display panel in response to the first color coordinate value, generates a target color coordinate value in response to the sample pixel value, and generates a first mapping table in response to the first color coordinate value, the first parameter and the target color coordinate value.

Abstract: Provided is a steel wire rod for a high strength and high toughness spring having excellent cold workability, the steel wire rod having a composition comprising: in weight %, C: 0.4 to 0.7%, Si: 1.5 to 3.5%, Mn: 0.3 to 1.0%, Cr: 0.01 to 1.5%, Ni: 0.01 to 1.0%, Cu: 0.01 to 1.0%, B: 0.005 to 0.02%, Al: 0.1% or less, O: 0.0020% or less, P: 0.02% or less, S: 0.02% or less, N: 0.02% or less, remainder Fe, and other unavoidable impurities, having a microstructure formed of ferrite and pearlite, and in which a prior (before cooling) austenite grain size is 8 ?m or less.

Abstract: Decarburization-restrained steel and manufacturing method thereof are disclosed. Steel includes a boron (B)-concentrated layer formed on its surface to prevent carbon of the steel from being in contact with oxygen in atmosphere to thus restrain decarburization of the steel. The steel includes a boron-concentrated layer with a thickness of 3 mm or larger formed on the surface of the steel. The method of manufacturing decarburization-restrained steel includes cooling steel containing 0.001 wt % to 0.02 wt % of boron (B) at a cooling speed of 0.5° C./s to 25° C./s at an austenite+ferrite two-phase region.

Abstract: Provided is a steel wire rod for a high strength and high toughness spring having excellent cold workability, the steel wire rod having a composition comprising: in weight %, C: 0.4 to 0.7%, Si: 1.5 to 3.5%, Mn: 0.3 to 1.0%, Cr: 0.01 to 1.5%, Ni: 0.01 to 1.0%, Cu: 0.01 to 1.0%, B: 0.005 to 0.02%, Al: 0.1% or less, O: 0.0020% or less, P: 0.02% or less, S: 0.02% or less, N: 0.02% or less, remainder Fe, and other unavoidable impurities, having a microstructure formed of ferrite and pearlite, and in which a prior (before cooling) austenite grain size is 8 ?m or less.