Abstract: Provided is a roller, and more particularly, to a rotary shaft of the upper part of a rolling wheel, having an inclined surface formed along the circumference of an outer diametral surface thereof, is inserted into at least one coupling groove formed on a transfer bracket, a thrust member is provided at the upper part of the rotary shaft so as to allow a thrust load to be concentrated on the upper end of the rotary shaft or the thrust member, and a radial member is provided at the inner surface of the coupling groove and the rotary shaft positioned at the lower part of the thrust member, thereby supporting a radial load.

Abstract: Provided is a roller, and more particularly, to a rotary shaft of the upper part of a rolling wheel, having an inclined surface formed along the circumference of an outer diametral surface thereof, is inserted into at least one coupling groove formed on a transfer bracket, a thrust member is provided at the upper part of the rotary shaft so as to allow a thrust load to be concentrated on the upper end of the rotary shaft or the thrust member, and a radial member is provided at the inner surface of the coupling groove and the rotary shaft positioned at the lower part of the thrust member, thereby supporting a radial load.

Abstract: The present invention relates to an UML unification model system, in particular to a system for metamodeling transformation to guarantee interoperability between an UML model of IEC 61850 and an UML model of IEC 61970. According to the invention, all IEC 61970 smart grid application using IEC 61850 data source easily obtains interoperability between applications and actively react to change of international standard because application developers use data by referring to a single UML IEC 61850/61970 unified model and refer to a single UML model reflecting flexibly constant modification of IEC standard, if any.

Abstract: The present invention relates to a method for metamodeling unification, in particular to a method for metamodeling unification to guarantee interoperability between an UML model of IEC 61850 and an UML model of IEC 61970. According to the invention, all IEC 61970 smart grid application using IEC 61850 data source easily obtains interoperability between applications and actively react to change of international standard because application developers use data by referring to a single UML IEC 61850/61970 unified model and refer to a single UML model reflecting flexibly constant modification of IEC standard, if any.

Abstract: The present invention relates to a metamodeling unification system, in particular to a system for metamodeling unification to guarantee interoperability between an UML model of IEC 61850 and an UML model of IEC 61970. According to the invention, all IEC 61970 smart grid application using IEC 61850 data source easily obtains interoperability between applications and actively react to change of international standard because application developers use data by referring to a single UML IEC 61850/61970 unified model and refer to a single UML model reflecting flexibly constant modification of IEC standard, if any.

Abstract: The present invention relates to a rail and a door roller of a window and door system and a window operation apparatus for windows and doors using the same.