Abstract: Disclosed is a method for preparing a reduced graphene oxide-magnesium nanocrystal composite. The method includes contacting graphene oxide with a first reducing agent to prepare a reduced graphene oxide, and co-reducing the reduced graphene oxide and a precursor of magnesium in the presence of a second reducing agent to prepare a reduced graphene oxide-magnesium nanocrystal composite, wherein by adjusting the amount of the first reducing agent in contact with the graphene oxide, the size of the magnesium nanocrystals in the composite may be controlled.

Abstract: A hydrogen storage composite material includes: a graphene oxide framework provided as a porous structure and having an average pore diameter of 1 to 2 nm; and the graphene oxide framework is impregnated with a metal hydride, the graphene oxide framework comprises: a graphene oxide; and a linker connecting the graphene oxide.

Abstract: Various embodiments of the invention describe an environmentally stable, and exceptionally dense hydrogen storage (6.5 wt % and 0.105 kg H2/L in the total composite, 7.56 wt % in Mg) using atomically thin and gas-selective reduced graphene oxide sheets as encapsulants. Other approaches to protecting reactive materials involve energy intensive introduction of considerable amounts of inactive, protective matrix which compromises energy density. However, these multilaminates are able to deliver exceptionally dense hydrogen storage far-exceeding 2020 DOE target metrics for gravimetric capacity (5.5 wt %), and ultimate full-fleet volumetric targets (0.070 kg H2/L) for fuel cell electric vehicles. Methods of stabilizing reactive nanocrystalline metals in zero-valency also has wide-ranging applications for batteries, catalysis, encapsulants, and energetic materials.

Abstract: A nickel-doped Mg nanocrystals encapsulated by molecular-sieving reduced graphene oxide (rGO) layers is disclosed. Dual-channel doping, which combines external (rGO strain) and internal (Ni doping) mechanisms, efficiently promotes both hydriding and dehydriding processes of Mg nanocrystals, simultaneously improving both the kinetic and thermodynamic properties of the material. The composite achieves both high hydrogen storage capacity and excellent kinetics while maintaining robustness. The realization of three complementary functional components in one material-environmentally friendly and earth-abundant Mg for storage, Ni dopants for catalysis, and rGO layers for encapsulation-breaks new ground in metal hydrides and makes solid-state materials viable candidates for hydrogen-fueled applications.

Abstract: The disclosure provides nanostructured composites of graphene derivatives and metal nanocrystals for gas storage and gas separation.

Abstract: Various embodiments of the invention describe an environmentally stable, and exceptionally dense hydrogen storage (6.5 wt % and 0.105 kg H2/L in the total composite, 7.56 wt % in Mg) using atomically thin and gas-selective reduced graphene oxide sheets as encapsulants. Other approaches to protecting reactive materials involve energy intensive introduction of considerable amounts of inactive, protective matrix which compromises energy density. However, these multilaminates are able to deliver exceptionally dense hydrogen storage far-exceeding 2020 DOE target metrics for gravimetric capacity (5.5 wt %), and ultimate full-fleet volumetric targets (0.070 kg H2/L) for fuel cell electric vehicles. Methods of stabilizing reactive nanocrystalline metals in zero-valency also has wide-ranging applications for batteries, catalysis, encapsulants, and energetic materials.

Abstract: A method in which a base station manages information for D2D communication, which is direct communication between terminals, is provided. The base station receives a first message that requests a configuration of a first open discovery service that searches for a first terminal and at least one terminal to perform D2D communication. The base station determines whether a resource to allocate to the first terminal exists. The base station stores first information for providing the first open discovery service based on the determination result.

Abstract: Disclosed are a method and apparatus for managing a cloud virtual base station system. The present invention includes setting initial resources and driving or downloading an execution file or environment file of the cloud virtual base station system and monitoring or managing a state for a failure, radio resources, or the execution file or the environment file of the cloud virtual base station system.

Abstract: Disclosed are a method for allocating a resource to a D2D link of a base station, including determining a D2D link resource to be allocated to the D2D link among cellular resources of the base station, and transmitting uplink control information including information on the D2D link resource to at least two terminals which are connected by the D2D link among a plurality of cellular terminals connected to the base station, and a method for transmitting/receiving data to and from a terminal, including: searching for a white space of cellular resources; transmitting a search result for the white space to a base station of coverage to which the terminal belongs; receiving resource information determined depending on the search result; and transmitting/receiving data to and from the adjacent terminals through the D2D link based on the resource information.

Abstract: When receiving a detachment notification message informing of detachment of a first D2D device, a D2D server in a device-to-device (D2D) communication system performs a D2D communication release procedure of an opponent D2D device which is communicating with the first D2D device, and deletes information for the D2D communication of the opponent D2D device.

Abstract: A method and apparatus for managing a cloud virtual base station system are disclosed. The present invention comprises configuring an initial resource and reconfiguring the resource to add or remove a resource of an execution file of the cloud virtual base station system, monitoring an error of the cloud virtual base station system, a wireless resource, a status of the execution file, or a configuration status of the reconfigured resource, managing configuration information of a list of software added or removed during an operation, controlling the cloud virtual base station system in a predetermined specific mode, managing hardware information, file information, or control information of each module of the cloud virtual base station system, and managing the execution file for each module of the cloud virtual base station system by adding or removing the predetermined specific mode initially or during an operation.

Abstract: An exemplary embodiment of the present invention provides a method for managing, by a management system, an enterprise zone. The management system constructs information on a plurality of small cell base stations and at least one terminal. The management system allocates at least one closed subscriber group (CSG) ID to the enterprise zone including cells of the small cell base stations. Further, the management system transmits a message for adding the CSG ID to a whitelist of the terminal to the terminal.

Abstract: A method in which a base station manages information for D2D communication, which is direct communication between terminals, is provided. The base station receives a first message that requests a configuration of a first open discovery service that searches for a first terminal and at least one terminal to perform D2D communication. The base station determines whether a resource to allocate to the first terminal exists. The base station stores first information for providing the first open discovery service based on the determination result.

Abstract: A method of providing a physical cell identity (PCI) assignment by a management server for small-cell base stations (BSs) in a heterogeneous network environment includes setting a location coordinate and radius for the small-cell BSs; grouping every first preset number of small-cells together to define one femto zone; constructing a location map for each femto zone; grouping every second preset number of femto zones to define one femto group; and constructing a location map for each femto group.

Abstract: The present invention relates to a short range wireless communication device for providing an application service based on an area. In particular, an apparatus for providing an application service based on an area in a small cell including a femtocell base station or a WiFi Access Point, the apparatus including a communication unit to receive a list of application services from an Application Service Provisioning Server, select and download at least one application service from the received list, an application service database to store the at least one downloaded application service, a service controller to install the at least one downloaded application service, or uninstall an installed application service, a user equipment access detector to detect a user equipment entering or exiting a service area, and a user equipment database to store an identifier and information of the user equipment entering or exiting the service area.

Abstract: A method and apparatus for managing a cloud virtual base station system are disclosed. The present invention comprises configuring an initial resource and reconfiguring the resource to add or remove a resource of an execution file of the cloud virtual base station system, monitoring an error of the cloud virtual base station system, a wireless resource, a status of the execution file, or a configuration status of the reconfigured resource, managing configuration information of a list of software added or removed during an operation, controlling the cloud virtual base station system in a predetermined specific mode, managing hardware information, file information, or control information of each module of the cloud virtual base station system, and managing the execution file for each module of the cloud virtual base station system by adding or removing the predetermined specific mode initially or during an operation.

Abstract: A method of providing a physical cell identity (PCI) assignment by a management server for small-cell base stations (BSs) in a heterogeneous network environment includes setting a location coordinate and radius for the small-cell BSs; grouping every first preset number of small-cells together to define one femto zone; constructing a location map for each femto zone; grouping every second preset number of femto zones to define one femto group; and constructing a location map for each femto group.

Abstract: Disclosed are a D2D direct communication method and apparatus in a cloud base station system. The present invention includes receiving a measurement result, including information about D2D proximity or interference from other devices, from each of a first device and a second device, determining whether or not to admit D2D direct communication between the first device and the second device based on the measurement results, sending radio resource information to a second base station and receiving radio resource information of the second base station if it is determined that the D2D direct communication is admitted, negotiating radio resources, allocated for the D2D direct communication, with the second base station using the internal primitive, and allocating radio resources to the first device based on the negotiation.

Abstract: Disclosed are a method and apparatus for managing a cloud virtual base station system. The present invention includes setting initial resources and driving or downloading an execution file or environment file of the cloud virtual base station system and monitoring or managing a state for a failure, radio resources, or the execution file or the environment file of the cloud virtual base station system.

Abstract: A method of managing a service mode of a femto cell base-station and access allowance for a terminal is disclosed. The method of managing access allowance includes receiving a first access allowance change request for a terminal, and transmitting a second access allowance change request for the terminal to a mobility management entity (MME) in response to the first access allowance change request. With the method of the example embodiments of the present invention, the service mode of the femto base-station and the access allowed terminal can be changed in real time according to a situation of the user. Accordingly, quality of service can be improved and efficient management of the femto base-station can be achieved through interference control between the macro base-station and the femto base-station.