Abstract:
The present invention relates to a method for protecting MU-MIMO (Multi User-Multiple Input Multiple Output) data through a multi-RTS/CTS frame exchange in a MU-MIMO based wireless communication system. The method of the present invention comprises: a process where an indicator for VHT data protection is added to an RTS frame, using the structure of an RTS/CTS frame for an existing legacy terminal during the multi RTS/CTS frame exchange; a process where an access point designates and then transmits the duration period of the RTS frame while transmitting the RTS frame; and a process where wireless terminals up to the (n-1)th terminal designate the duration period of the CTS frame as ‘0’ and send the designated duration period, while only the n-th wireless terminal designates NAV for data protection.
Abstract:
The present invention provides an apparatus and method for manufacturing a fuel cell membrane-electrode assembly by forming a catalyst layer, which has uniform distribution, excellent porosity, and excellent bondability to a polymer electrolyte membrane, on a metal roll by an electrospray process and transferring the catalyst layer to a polymer electrolyte membrane.
Abstract:
Disclosed is a method of manufacturing an organic light emitting device, which comprises the steps of successively stacking a bottom electrode, an organic layer including an emission layer, and a top electrode, the method further comprising the step of: surface-treating the bottom electrode with ion beam etching before stacking the organic layer. By effectively removing impurities such as polymer materials or oxidation films, which are formed on the bottom electrode of the organic light emitting device, not only electron injection and hole injection in the organic light emitting device progress smoothly, but also an operation voltage is lowered and performance reliability can ensured because the surface roughness of the bottom electrode is maintained at the same level before and after ion milling.
Abstract:
A microwave lens having an array of electronic inductive capacitive cells wherein each cell includes an electrically conductive pattern which responds to incident microwave electromagnetic energy as an LC resonator. At least one of the cells includes at least one MEMS device which is movable in response to an electrical bias to thereby vary the resonant frequency of that cell. In order to bias the MEMS device, an electrical insulating layer extends along a portion of the pattern of the cell and to both sides of the MEMS device. An electrically conductive strip then extends over the insulating layer so that the conductive strip is electrically insulated from the pattern while electrically connected to the MEMS device.
Abstract:
The present invention provides an electrode for a polymer electrolyte membrane fuel cell (PEMFC) and a method for forming a membrane-electrode assembly (MEA) using the same, in which carbon nanofibers are added to a catalyst layer to increase the mechanical strength of the catalyst layer and to maintain the thickness of the catalyst layer after operation for a long time, thus preventing a reduction in physical durability of the fuel cell, and cerium-zirconium oxide (CeZrO4) as a radical inhibitor is added to the catalyst layer, thus preventing a reduction in chemical durability of the fuel cell. As a result, it is possible to physically and chemically increase the performance and durability of the fuel cell membrane-electrode assembly in a robust manner and minimize the reduction in performance after operation for a long time.
Abstract:
Disclosed is a method for preparing nickel or palladium nanoparticles supported on a carbon support. To a mixture solution wherein a stabilizer is dissolved in 1,2-propanediol, a carbon support is added to prepare a dispersion. Then, a precursor solution wherein a nickel or palladium precursor dissolved in 1,2-propanediol is mixed therewith and stirred. Then, nickel or palladium nanoparticles supported on the carbon support are prepared by reduction. The disclosed method for preparing nickel or palladium nanoparticles supported on a carbon support allows preparation of nanoparticles with narrow particle size distribution and good dispersibility through a simple process and the resulting nickel or palladium nanoparticles may be usefully applied, for example, as electrode materials of fuel cells.
Abstract:
The present invention provides a method of synthesizing a nano-sized transition metal catalyst on a carbon support, including dissolving a stabilizer in ethanol thus preparing a mixture solution, adding a support to the mixture solution thus preparing a dispersion solution, dissolving a transition metal precursor in ethanol thus preparing a precursor solution, mixing the precursor solution with the dispersion solution with stirring, and then performing reduction, thus preparing the nano-sized transition metal catalyst. This method enables the synthesis of transition metal nanoparticles supported on carbon powder having a narrow particle size distribution and a wide degree of dispersion through a simple process, and is thus usefully applied to the formation of an electrode material or the like of a fuel cell.
Abstract:
A refrigerator which can control a supercooling degree corresponding to user's taste or kinds of food, and a cooling control method thereof are disclosed. The refrigerator has a function of supercooling a drink, and includes an input unit to select a slush level for adjusting a supercooling degree of the drink in response to a user's command, a memory unit to store information about a supercooling temperature of the drink corresponding to a selected slush level, and a controller to adjust the supercooling degree of the drink by controlling a temperature within the supercooling compartment based on the information about the supercooling temperature of the drink stored in the memory unit.
Abstract:
The present invention relates to a fermentation apparatus comprising a storage compartment which is formed with an accommodating space for storing food and at least one of a heating part and a cooling part to ferment the food in the storage compartment, further comprising a sensor to sense a fermentation level of the food; an input part comprising a memory button allowing to memorize the fermentation level in a state that the food is fermented to an extent that a user wants to memorize; and a controller to control operation of at least one of the heating part and the cooling part, and store a fermentation value from the sensor as a custom fermentation value if the memory button is selected. Thus, the present invention provides a fermentation apparatus for customizing a fermentation level and a method thereof, which memorizes a desired fermentation level and repeatedly provides food at a desired fermentation level by selecting a memorized fermentation level.
Abstract:
A microwave lens having an array of electronic inductive capacitive cells wherein each cell includes an electrically conductive pattern which responds to incident microwave electromagnetic energy as an LC resonator. At least one of the cells includes at least one MEMS device which is movable in response to an electrical bias to thereby vary the resonant frequency of that cell. In order to bias the MEMS device, an electrical insulating layer extends along a portion of the pattern of the cell and to both sides of the MEMS device. An electrically conductive strip then extends over the insulating layer so that the conductive strip is electrically insulated from the pattern while electrically connected to the MEMS device.