Abstract:
본 발명은 이차원 평면배열 안테나를 사용하는 FDD (frequency division duplex) massive MIMO (Multiple-Input Multiple-Output) 시스템에서, 제한된 양의 하향링크 전파 자원만을 사용하여 하향링크 이차원 공간채널 추정을 위한 채널상태 정보 기준신호(channel state information reference signal, CSI-RS)를 효과적으로 전송하고, 이차원 공간채널에서 공간분할 다중화(spatial multiplexing, SM)와 공간분할 다중접속 (space division multiple access, SDMA) 기술을 최적 선택하여 수행하는 hybrid SM & SDMA 기술을 제안한다. 이를 위해, 수평 차원(horizontal dimension)에서 하향링크 채널 간 공간상관도가 높은 공간 원소(space element,SE)들과 이에 대응하는 vertical dimension의 SE들을 묶어서 space resource block(SRB)을 정의하고, 매 transmit time interval(TTI) 마다, 각 SRB에서는 선택된 하나의 horizontal SE에 대응하는 vertical dimension SE들에서 채널 추정을 위한 CSI-RS들을 전송하는 기술을 제안한다. UE(user equipment)가, 다른 TTI에서 수신되는 동일한 SRB에 속하는 서로 다른 수평 차원(horizontal dimension)의 SE들의 채널간 공간 상관도와 동일 TTI에서 수신되는 다른 SRB에 속하는 수평 차원(horizontal dimension)의 SE들의 채널간 공간 상관도를 추정하고, 해당 UE의 SRB의 크기를 최적의 크기로 변경하기 위한 정보를 eNodeB로 피드백 하는 기술을 제안한다. UE는 각 SRB에서 전송되는 CSI-RS들을 통해 하향링크 채널을 추정하고, 각 UE는 선호하는 SRB의 index와 해당 SRB의 vertical dimension에서의 랭크 및 channel quality information(CQI)를 eNodeB로 피드백 하는 기술을 제안한다. 각 UE는 랭크를 결정할 때, vertical dimension에서는 full 랭크까지 전송 가능하며, 수평 차원(horizontal dimension)에서는 각 SRB에서 단일 랭크만 전송하도록 한다.
Abstract:
PURPOSE: A transmitting and receiving device for transmitting and receiving channel state information reference signals at a giant multiple input multiple output system operating in a frequency division duplex mode and a method thereof are provided to effectively transmit the channel information of various antennas and enable a receiving device to effectively estimate downlink channel state information using only downlink resources of limited amount. CONSTITUTION: A control part (1030) generates a signal for each beam to be transmitted through each antenna port. The control part forms the beam by precoding the signal for the each beam generated through a beam forming vector. The control part separates the resource reusing groups of an arbitrary number through grouping beams which is sharing the same resources of the formed beam. The control part transmits the beam to a receiving device by allocating the resource by the resource reusing group. The control part allocates the resources by determining the beam in which a transmitting device has a maximum benefit using feedback information transmitted from the receiving device. [Reference numerals] (1010) Wireless communication part; (1020) Storage part; (1030) Control part; (1031) Signal generation part by beams; (1032) Precoding part; (1033) Scheduler
Abstract:
A system and a method for measuring rotation resistance of molten metal are provided to detect viscosity changed after mixing of molten metal and a mixed material in real time by rotating a stirrer at a predetermined speed and by measuring surface friction resistance between the stirrer and the molten metal. A system for measuring rotation resistance of molten metal including an alloy manufacturer equipped with a furnace heating a crucible, the crucible filled with molten metal and a mixing material and a stirrer stirring molten metal with the mixing material, comprises: a stirrer(7) rotatably stirring molten metal inside the crucible, a coupling(8) connecting a motor shaft with a shaft of the stirrer, a servo-motor(9) controlling a rotation speed of the stirrer, a funnel(11) installed in an upper portion of the hollow shaft, which puts powder or chip-type components for mixed alloy to molten metal through the stirrer, a fixing jig(12) fixing the servo-motor, a thermocouple which is a temperature measurer used for maintaining a temperature of the furnace, a thermocouple which is a temperature measurer used for maintaining a temperature of the crucible, a controller equipped with a servo-motor driver, a temperature control indicator, an electric furnace controller and so on, and a data acquisition system connected with the controller, which includes a computer and software for acquiring and storing acquisition data.
Abstract:
A mixing material injection system is provided to uniformly improve the structure of a mixture of molten metal and a mixing material, and prepare a material with excellent physical properties and mechanical properties by injecting powder or chips of a component that is mixed with molten metal during stirring into molten metal. An injection system of a mixing material for alloy manufacturing comprises a stirrer(7), a shaft connecting coupling(8), a servo motor(9), a funnel(11), and a fixing jig(12), wherein a semicircular cross-sectional shaped helix is processed in a hollow portion of the servo motor from a rotational direction to a downward direction to promptly inject a powder or chip type component into molten metal inside a crucible(5) along a spiral steel wire without loss of the component such that the component is mixed with the molten metal, and vanes with width corresponding to 1/2 hollow cross-sectional shaped diameter of the stirrer are attached to an inner part of a hollow shaped stirrer to accurately compare and detect viscosity changes of molten metal by promptly stirring molten metal and an input component, thereby increasing the rotary resistance.
Abstract:
PURPOSE: A method for manufacturing a lead-tab for an anode is provided to prepare a lead-tab for an anode of a secondary battery by a simple process at inexpensive costs, thereby lowering production cost of lithium ions or a lithium polymer secondary battery. CONSTITUTION: A method for manufacturing a lead-tab for an anode comprises a preparation step of preparing a copper plate as a raw material of a current collector; a plating step of plating a copper plate with nickel; a rolling step of rolling nickel-plated copper plate; and a heat treatment step of heating the rolled nickel-plated copper plate. The heat treatment temperature is 300~500 °C.
Abstract:
본 발명은 용융금속 회전저항 계측시스템 및 그 방법에 관한 것으로, 그 목적은 가열로로 가열된 도가니 내에 모재 금속 단독 또는 모재에 혼입되는 혼입재(또는 강화재)를 혼합 후 가열, 용융하여 일정온도에서 일정 규격으로 설계 제작된 교반자를 계획된 회전속도로 회전시켜 교반자와 용융금속 간의 표면마찰저항을 정밀하게 계측함으로써 용융금속 및 혼입재 투입 후의 변화된 점도를 실시간으로 비교 검출할 수 있는 장치 및 그 방법을 제공하는 데 있다. 본 발명의 구성은 도가니 내에 모재 금속 단독 또는 모재에 혼입되는 혼입재를 혼합 후 가열, 용융하여 일정온도에서 일정 규격으로 설계 제작된 교반자를 계획된 회전속도로 회전시키면서 교반자를 회전시키는 서보-모터에 걸리는 미소한 부하로 인한 서보 모터의 소비전력(전류) 변화량을 측정하여 용융금속의 점도변화를 검출하는 방법 및 이를 수행하는 장치 수단을 그 기술적 사상의 특징으로 한다. 점도, 용융금속, 회전저항, 계측시스템, 교반자
Abstract:
The present invention relates to a wireless communication system, and more specifically, to a data exchange apparatus which can effectively transmit a channel state information reference signal (CSI-RS) for two-dimensional downlink space channel estimation by only using a limited amounted of downlink frequency resources in a frequency division duplex (FDD) massive MIMO system using a two-dimensional plane alignment antenna and a method thereof.
Abstract:
A method for producing Ba8Al16Si30 clathrate thermoelectric material is provided to improve thermoelectric properties comprising seeback coefficient or factor and electric conductivity by properly selecting annealing conditions. Ba element, Al element, and Si element are prepared as start material, and the start materials are blended to make a compound. The compound is arc-molten to produce Ba8Al16Si30. For homogenization of a phase and phase change, the molten material is annealed at the temperature of 700 deg.C. The annealing process is carried out during 5 hours.