http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
OFDMA 스마트 안테나 시스템을 위한 도래각 추정 기반의 적응 빔 형성 알고리즘
윤영호,박윤옥,박형래,Yun, Young-Ho,Park, Yoon-Ok,Park, Hyung-Rae 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.12A
본 논문에서는 orthogonal frequency-division multiple-access 스마트 안테나 시스템을 위한 효율적인 도래각 추정 기반의 적응 빔 형성 알고리즘을 제안한다. 제안된 알고리즘은 추정된 도래각 정보를 이용하여 원하는 신호의 방향으로 주 빔 (main beam)을 형성하는 반면, 간섭 신호의 방향에는 null을 형성함으로써 간섭 신호를 효율적으로 제거한다. 또한, 다중 경로 신호에 대한 빔 형성 출력들을 효율적으로 결합함으로써 공간 다이버시티 이득을 얻을 수 있다. 제안된 알고리즘의 효율성을 입증하기 위해 셀룰러 이동통신 환경에서 WiBro 시스템을 목표 시스템 (target system)으로 설정하여 알고리즘의 성능을 분석하고 least-sqaures 빔 형성 알고리즘과 성능을 비교한다. In this paper, an efficient direction-r)f-arrival based adaptive beamforming algorithm for orthogonal frequency-division multiple-access smart antenna systems is proposed. The proposed algorithm provides a high performance by steering main beams to the directions of a desired signal, whereas steering nulls to the directions of the interference, using the estimated directions. The beamforming outputs obtained by steering the main beams to the distinct directions of resolvable multipath signals are combined in a maximal ratio manner to exploit angular diversity gain. The performance elf the proposed algorithm is finally evaluated in cellular mobile environments to verify its efficiency and is compared with that of least-squares beamforming algorithm, by taking the WiBro system as a target system.
광대역 이동통신 환경에서 초 분해능 방향 탐지 알고리즘의 성능 비구 분석
윤영호,박윤옥,박형래,Yun Young-Ho,Park Yoon-Ok,Park Hyung-Rae 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.8A
본 논문에서는 광대역 이동통신 환경에서 대표적인 초 분해능 방향 탐지 알고리즘들의 도래각 추정 성능을 비교, 분석한다. 먼저, 이동통신 환경에서 발생하는 angular spread 현상을 고찰하고 광대역 OFDMA 신호의 벡터채널 모델을 유도한다. 또한, OFDMA 스마트 안테나 시스템을 위한 방향 탐지 시스템의 구조를 제시하고 광대역이동통신 환경에서 WiBro 시스템을 목표 시스템(target system)으로 설정하여 초 분해능 방향 탐지 알고리즘의 도래각 추정 성능을 시뮬레이션을 통해 비교, 분석한다. In this paper, the performances of representative high resolution direction finding algorithms are evaluated and compared in wideband mobile environments. The angular spread phenomenon in mobile environments is first investigated and then a vector channel model for wideband OFDMA signals is derived. A direction finding system architecture for OFDMA smart antenna systems is proposed and finally the performances of high resolution direction finding algorithms are evaluated in wideband mobile environments by taking the WiBro system as a target system.
Lactobacillus casei YIT9018 의 생존경쟁기작에 관한 연구
윤영호,윤계병,김현욱 ( Young Ho Yoon,Que Byung Yoon,Hyun Uk Kim ) 한국축산학회 1981 한국축산학회지 Vol.23 No.3
The competitive survival mechanism of Lactobacillus casei YIT9018 has been studied using Escherichia coli LDTMI in MRS and TGY media. The results obtained are summarized as follows; 1. When two oragisms were cultured together, the growth of E. coli was inhibited greatly by L. casei in MRS medium, but in TGY medium, E. coli was inhibited only slightly. 2. The growth inhibition of E. coli by L. casei was studied at the controlled pHs (pH 7, 6, 5, and 4) of MRS broth. The growth inhibition of E. coli was not distinct at pH 7 and 6, but at pH 5 and 4, E. coli was inhibited distinctively. This result means L. casei produced E. coli-inhibiting substances during its growth below pH 6.0 in MRS broth. 3. The growth inhibition of E. coli by L. casei was analyzed by cylinder plate method. MRS broth adjusted to pH 5 exhibited the inhibition zone of 4.2 ㎜ diameter against E. coli while L. casei cultured MRS broth exhibited the inhibition zone of 10 ㎜ diameter at the same pH. Inhibition zone exhibited by L. casei cultured MRS broth was the largest one among the three cultured media. 1t is apparent that production of E. coli-inhibiting substances (LC factor) by L. casei in addition to the acid production. 4. Sodium acetate in MRS medium was found to play the important role in the synthesis of LC factor by L. casei The role of sodium acetate was also evidenced in TGY medium by exhibiting the increased inhibitory activity when TGY medium was supplemented with sodium acetate and 0.2 % glucose. 5. L. casei YIT9018 was found to compete and multiply in the natural habitat by producing acid as well as LC factor.
윤영호(Young Ho Yoon),양영성(Young Sung Yang) 한국강구조학회 1994 韓國鋼構造學會誌 Vol.6 No.3
The method using structural welded wire-fabric having been introduced as a plan that simplify the stage of processing and assembling reinforcing rods and increase the efficiency of them in reinforced concrete construction. The purpose of this study, by investigating, contrasting specification of each nation, is to suggest a fundamental data fit for structural purpose and required to establish standard specification for structural welded wire fabric. 1) As a result of analyzing a present industrial standards, because wire-fabric is confirmed for the use of crack controlling, the standard for structural purpose having been required. 2) Elongation is used as a method of measuring ductility in Europe, ISO, whereas reduction of area is used in Korea, Japan, U.S.A. Accordingly, it is necessary to change the method into elongation and elongation percent is established with gage length of 5d_b, elongation of 12%. 3) We will contain satisfying bond and anchorage in case that probability of 95%, inspection method of ISO, is adopted. 4) The device of DIN 488 and BS 4483, which is used for carrying out the shear test, shall be recommended, and testing jig of KS shall be improved.
윤영호(Young Ho Yoon),양영성(Young Sung Yang) 한국강구조학회 1994 韓國鋼構造學會誌 Vol.6 No.3
The test is carried out in order to make clear the mechanical properties of the structural welded wire fabric with variables such as tensile strength, reduction of area, elongation, melding point shear strength and bendability. The results are as follows : 1) The test piece across the welds about tensile strength is slightly higher than between the welds, and the elongation is opposite. 2) Welding point shear strength is considerably high, but if the strength is much increased, tensile strength get low by brittleness of welding point. Accordingly it is necessary to establish the shear strength as 15 kgf/㎟(150N/㎟). 3) The bend test should be carried out at welding point, the ductility of which is the smallest.