Abstract: The present invention relates to a method of managing a trunk, and querying and ascertaining a ring-back sound to provide the ring-back sound in a subscriber-based ring-back sound service. In the trunk management method, a terminating mobile switching center (32) requests the intelligent peripheral (50) to release a trunk call when the terminating mobile switching center recognizes the answer of the terminating subscriber or when a first predetermined period of time has elapsed from a time when it is recognized that a corresponding ring-back sound is provided to the originator. Further, the intelligent peripheral (50) requests the terminating mobile switching center (32) to release the trunk call when a second predetermined period of time has elapsed from a time when the ring-back sound is provided.

Abstract: The present invention relates to a method of managing a trunk, and querying and ascertaining a ring-back sound to provide the ring-back sound in a subscriber-based ring-back sound service. In the trunk management method, a terminating mobile switching center (32) requests the intelligent peripheral (50) to release a trunk call when the terminating mobile switching center recognizes the answer of the terminating subscriber or when a first predetermined period of time has elapsed from a time when it is recognized that a corresponding ring-back sound is provided to the originator. Further, the intelligent peripheral (50) requests the terminating mobile switching center (32) to release the trunk call when a second predetermined period of time has elapsed from a time when the ring-back sound is provided.

Abstract: Disclosed herein is a method and apparatus for managing ring-back sounds in a subscriber-based ring-back sound service. The method includes the first step of storing common ring-back sounds and reporting details of use of the common ring-back sounds, the second step of storing individual ring-back sounds and reporting details of use of the individual ring-back sounds, and the third step of statistically compiling the reported details of use and determining whether to maintain storage of the ring-back sounds based up the statistically complied details. A method and apparatus for presenting and changing ring-back sounds based upon the ring-back sound managing method and apparatus are provided.

Abstract: Sealant compositions particularly suitable for solid oxide fuel cell sealant are provided and preferably comprise glass matrix and ceramic fiber, wherein glass matrix and ceramic fiber are mixed in an volume ratio of 25:75-75:25 in the sealant, and the ceramic fibers are preferably uniformly dispersed in the sealant to exhibit an orientation. Methods to manufacture the sealant compositions also are provided. Particularly preferred sealant compositions of the invention can efficiently avoid undesired viscous flow of glass matrix, precisely locate the stack of fuel cell on the region to be sealed, and maintain uniform sealing ability under various changes in size of the fuel cell stack.

Abstract: The present invention relates to a method of preparing a polyether poly(N-substituted urethane) comprising an electrolytic compound and a polymer matrix, wherein the polymer matrix is a copolymer comprising polyether unit and polyurethane unit and has 50,000-2,000,000 of a weight average molecular weight, where N-positions of the polyurethane unit are substituted with oligo(ethylene oxide) derivatives which provide flexibility and electrolytic conduction of the polymer matrix by controlling its length, composition, structure and crosslinked degree. Accordingly, the solid polymer electrolyte of the present invention provides excellent thermal stability, electrochemical stability and mechanical properties and thus, is suitable for use in polymer secondary batteries and electrochemical devices.

Abstract: The present invention relates to a method of preparing a polyether poly(N-substituted urethane) comprising an electrolytic compound and a polymer matrix, wherein the polymer matrix is a copolymer comprising polyether unit and polyurethane unit and has 50,000-2,000,000 of a weight average molecular weight, where N-positions of the polyurethane unit are substituted with oligo(ethylene oxide) derivatives which provide flexibility and electrolytic conduction of the polymer matrix by controlling its length, composition, structure and crosslinked degree. Accordingly, the solid polymer electrolyte of the present invention provides excellent thermal stability, electrochemical stability and mechanical properties and thus, is suitable for use in polymer secondary batteries and electrochemical devices.

Abstract: The present invention relates to a solid polymer electrolyte of polyether poly(N-substituted urethane) comprising an electrolytic compound and a polymer matrix, wherein the polymer matrix is a copolymer comprising polyether unit and polyurethane unit and has 50,000-2,000,000 of a weight average molecular weight, where N-positions of the polyurethane unit are substituted with oligo(ethylene oxide) derivatives which provide flexibility and electrolytic conduction of the polymer matrix by controlling its length, composition, structure and crosslinked degree. Accordingly, the solid polymer electrolyte of the present invention provides excellent thermal stability, electrochemical stability and mechanical properties and thus, is suitable for use in polymer secondary batteries and electrochemical devices.

Abstract: The present invention relates to a solid polymer electrolyte of polyether poly(N-substituted urethane) comprising an electrolytic compound and a polymer matrix, wherein the polymer matrix is a copolymer comprising polyether unit and polyurethane unit and has 50,000-2,000,000 of a weight average molecular weight, where N-positions of the polyurethane unit are substituted with oligo(ethylene oxide) derivatives which provide flexibility and electrolytic conduction of the polymer matrix by controlling its length, composition, structure and crosslinked degree. Accordingly, the solid polymer electrolyte of the present invention provides excellent thermal stability, electrochemical stability and mechanical properties and thus, is suitable for use in polymer secondary batteries and electrochemical devices.