Abstract: Proposed is to provide a size-varying bubble complex and a method of preparing the same. More specifically, the size-varying bubble complex and the method of preparing the same are proposed, wherein the bubble complex is capable of being repeatedly varied in size by changing phases of perfluorocarbon by external stimuli, by including a shell that encapsulates a core made of the perfluorocarbon and protects the core by expanding and contracting together when the core expands and contracts.

Abstract: Proposed is to provide a size-varying bubble complex and a method of preparing the same. More specifically, the size-varying bubble complex and the method of preparing the same are proposed, wherein the bubble complex is capable of being repeatedly varied in size by changing phases of perfluorocarbon by external stimuli, by including a shell that encapsulates a core made of the perfluorocarbon and protects the core by expanding and contracting together when the core expands and contracts.

Abstract: A contents providing system for providing video contents through a social service includes a memory storing computer-readable instructions; and one or more processors configured to execute the instructions to, manage information on a social network between users of the social service; and provide a together-watching function if at least one conversation partner is selected from a list of different persons related to a user according to the social network, wherein the together-watching function is a function that provides simultaneous display of a conversation screen with the at least one conversation partner and a video reproduction screen in which the video contents are reproduced.

Abstract: Proposed is to provide a size-varying bubble complex and a method of preparing the same. More specifically, the size-varying bubble complex and the method of preparing the same are proposed, wherein the bubble complex is capable of being repeatedly varied in size by changing phases of perfluorocarbon by external stimuli, by including a shell that encapsulates a core made of the perfluorocarbon and protects the core by expanding and contracting together when the core expands and contracts.

Abstract: A contents providing system for providing video contents through a social service includes a memory storing computer-readable instructions; and one or more processors configured to execute the instructions to, manage information on a social network between users of the social service; and provide a together-watching function if at least one conversation partner is selected from a list of different persons related to a user according to the social network, wherein the together-watching function is a function that provides simultaneous display of a conversation screen with the at least one conversation partner and a video reproduction screen in which the video contents are reproduced.