Abstract: Disclosed are a method and an apparatus for an instant messaging service to provide a schedule service. A schedule management server according to an example embodiment includes receiving a schedule creating request, selecting any one of a first type of calendar belonging to a chatroom in which the schedule creating request is created and a second type of calendar belonging to a user account which creates the schedule creating request, according to a schedule type included in the schedule creating request; and creating a schedule corresponding to the selected type of calendar.

Abstract: Disclosed are a method and an apparatus for an instant messaging service to provide a schedule service. A schedule management server according to an example embodiment includes receiving a schedule creating request, selecting any one of a first type of calendar belonging to a chatroom in which the schedule creating request is created and a second type of calendar belonging to a user account which creates the schedule creating request, according to a schedule type included in the schedule creating request; and creating a schedule corresponding to the selected type of calendar.

Abstract: Provided is a method of manufacturing a high-carbon hot-rolled steel sheet, including the steps of i) preparing high-carbon steel materials comprising C: 0.7 to 0.9%, Si: 0.5% or less, Mn: 0.1 to 1.5%, Cr: 0.5% or less, P: 0.05% or less, and S: 0.03% or less in wt % and remaining Fe and other inevitable impurities; ii) heating the high-carbon steel materials again and manufacturing a steel sheet by performing hot rolling in an austenite region in which a finishing temperature for the hot rolling is an Ar3 transformation temperature or higher; iii) rapidly cooling the steel sheet at 520 to 620° C. before phase transformation is started in a Run-Out Table (ROT); iv) uniformly maintaining a cooling retention temperature so that the cooled steel sheet is subject to phase transformation in any one temperature between 520 to 620° C.; and v) winding the steel sheet in the cooling retention temperature. Also provided is the high-carbon steel sheet made by the above-described method.

Abstract: A carbon steel sheet having high formability due to a microscopic and uniform carbide distribution and having a good characteristic of final heat treatment, and a manufacturing method thereof. The carbon steel sheet having excellent formability includes, in wt %, C at 0.2-0.5%, Mn at 0.1-1.2%, Si at less than or equal to 0.4%, Cr at less than or equal to 0.5%, Al at 0.01-0.1%, S at less than or equal to 0.012%, Ti at less than or equal to 0.5×48/14×[N]% to 0.03% when the condition of B and N is not satisfied, B at 0.0005-0.0080%, N at less than or equal to 0.006%, Fe, and extra inevitable elements; an average size of carbide is less than or equal to 1 ?m; and an average grain size of ferrite is less than or equal to 5 ?m.

Abstract: Provided is a method of manufacturing a high-carbon hot-rolled steel sheet, including the steps of i) preparing high-carbon steel materials comprising C: 0.7 to 0.9%, Si: 0.5% or less, Mn: 0.1 to 1.5%, Cr: 0.5% or less, P: 0.05% or less, and S: 0.03% or less in wt % and remaining Fe and other inevitable impurities; ii) heating the high-carbon steel materials again and manufacturing a steel sheet by performing hot rolling in an austenite region in which a finishing temperature for the hot rolling is an Ar3 transformation temperature or higher; iii) rapidly cooling the steel sheet at 520 to 620° C. before phase transformation is started in a Run-Out Table (ROT); iv) uniformly maintaining a cooling retention temperature so that the cooled steel sheet is subject to phase transformation in any one temperature between 520 to 620° C.; and v) winding the steel sheet in the cooling retention temperature. Also provided is the high-carbon steel sheet made by the above-described method.

Abstract: A carbon steel sheet having high formability due to a microscopic and uniform carbide distribution and having a good characteristic of final heat treatment, and a manufacturing method thereof. The carbon steel sheet having excellent formability includes, in wt %, C at 0.2-0.5%, Mn at 0.1-1.2%, Si at less than or equal to 0.4%, Cr at less than or equal to 0.5%, Al at 0.01-0.1%, S at less than or equal to 0.012%, Ti at less than or equal to 0.5×48/14×[N] % to 0.03% when the condition of B and N is not satisfied, B at 0.0005-0.0080%, N at less than or equal to 0.006%, Fe, and extra inevitable elements; an average size of carbide is less than or equal to 1 ?m; and an average grain size of ferrite is less than or equal to 5 ?m.

Abstract: A carbon steel sheet having high formability due to a microscopic and uniform carbide distribution and having a good characteristic of final heat treatment, and a manufacturing method thereof. The carbon steel sheet having excellent formability, includes, in wt %, C at 0.2-0.5%, Mn at 0.1-1.2%, Si at less than or equal to 0.4%, Cr at less than or equal to 0.5%, Al at 0.01-0.1%, S at less than or equal to 0.012%, Ti at less than or equal to 0.5×48/14×[N]% when the condition of B(atomic %)/N(atomic %)>1 is satisfied or by 0.5×48/14×[N]% to 0.03% when the condition of B and N is not satisfied, B at 0.0005-0.0080%, N at less than or equal to 0.006%, Fe, and extra inevitable elements; an average size of carbide is less than or equal to 1 ?m; and an average grain size of ferrite is less than or equal to 5 ?m.

Abstract: The present invention relates to a high carbon steel sheet that is superior in fatigue life and a method of manufacturing the high carbon steel sheet. The high carbon steel sheet includes about 0.75 wt % to about 0.95 wt % of carbon, smaller than about 1.8 wt % of silicon, about 0.1 wt % to about 1.5 wt % of manganese, about 0.1 wt %˜1.0 wt % of chromium, smaller than about 0.02 wt % of phosphorus, smaller than about 0.02 wt % of sulfur, a residual amount of iron, and inevitable impurities. A layer interval between laminar carbides included in the high carbon steel sheet is smaller than about 0.5 ?m. The high carbon steel sheet may include a fine pearlite having a lamellar structure. The fine pearlite included in the high carbon steel sheet may have a volume percentage of larger than about 90%. A ratio of length to width of the lamellar structure may be larger than about 10:1.

Abstract: A carbon steel sheet having high formability due to a microscopic and uniform carbide distribution and having a good characteristic of final heat treatment, and a manufacturing method thereof. The carbon steel sheet having excellent formability, includes, in wt %, C at 0.2-0.5%, Mn at 0.1-1.2%, Si at less than or equal to 0.4%, Cr at less than or equal to 0.5%, Al at 0.01-0.1%, S at less than or equal to 0.012%, Ti at less than or equal to 0.5×48/14×[N]% when the condition of B(atomic %)/N(atomic %)>1 is satisfied or by 0.5×48/14×[N]% to 0.03% when the condition of B and N is not satisfied, B at 0.0005-0.0080%, N at less than or equal to 0.006%, Fe, and extra inevitable elements; an average size of carbide is less than or equal to 1 ?m; and an average grain size of ferrite is less than or equal to 5 ?m.

Abstract: An engine hood door including a variable door handle is provided, in which a protruding length of the door handle from an outer side of the engine hood door is varied. The engine hood door includes a door handle having a handle portion and extending portions extending from both ends of the handle portion, each of the extending portions being movably engaged to a through-hole formed in the engine hood door, a resilient member, positioned between the extending portion penetrating the through-hole and an inner side of the engine hood door, for variably adjusting the protruding length of the handle portion protruding from an outer side of the engine hood door, and a locking pin fixed to each end of the extending portions for preventing the door handle from being released from the engine hood door. When the handle portion is pulled so as to open the engine hood door, the protruding length of the door handle from the outer side of the engine hood door is varied.

Abstract: In a locking and unlocking apparatus of an engine hood door, a stay is formed of a first arm and a second arm, with the stay being provided so as to fix a door of an engine hood in a fixed state. The first arm and the second arm are foldably connected to each other and pivotally connected to a frame and a door respectively. The lock of the first arm is automatically locked by a locking piece of the second arm at a portion in which the first arm and the second arm are arranged on a straight line for thereby maintaining an opened state of the door. The lock is unlocked from the locking piece with the locking piece being pulled by operation of a lever which is connected with the locking piece through a wire from a remote site, so that the door is closed.

Abstract: Disclosed is an opening angle regulating device of a side door for a heavy equipment, which is provided between a door frame and the side door to regulate an opening angle of the side door. The opening angle regulating device includes a rod whose one end is rotatably fixed onto the door frame, and a bracket fixed onto the side door, having a guide rail slidably fixed to the other end of the rod depending on opening and closure of the side door, the guide rail having a groove that fixes the other end of the rod if the side door is opened at a predetermined angle. Preferably, the opening angle of the side door is regulated as the position of the groove is adjusted on the guide rail.