멀티코어 DSP를 이용한 다중 안테나를 지원하는 SDR 기반 LTE-A PDSCH 디코더 구현

나용,안흥섭,최승원 (사)디지털산업정보학회 2019 디지털산업정보학회논문지 Vol.15 No.4

This paper presents a SDR-based Long Term Evolution Advanced (LTE-A) Physical Downlink Shared Channel (PDSCH) decoder using a multicore Digital Signal Processor (DSP). For decoder implementation, multicore DSP TMS320C6670 is used, which provides various hardware accelerators such as turbo decoder, fast Fourier transformer and Bit Rate Coprocessors. The TMS320C6670 is a DSP specialized in implementing base station platforms and is not an optimized platform for implementing mobile terminal platform. Accordingly, in this paper, the hardware accelerator was changed to the terminal implementation to implement the LTE-A PDSCH decoder supporting the multi-antenna and the functions not provided by the hardware accelerator were implemented through core programming. Also pipeline using multicore was implemented to meet the transmission time interval. To confirm the feasibility of the proposed implementation, we verified the real-time decoding capability of the PDSCH decoder implemented using the LTE-A Reference Measurement Channel (RMC) waveform about transmission mode 2 and 3.

변환요소에 따른 Looped Wire 탄성 변화에 관한 연구

나용인,김상철 원광대학교 치의학연구소 1990 圓光齒醫學 Vol.1 No.1

The purpose of this study was to evlauate and compare the effect of the variable factors of wire on the elastic properties of looped rectangular wire. Five variable factors were presented-material (Hi-T, blue Elgiloy), wire size (.016"×.022", .018"× .025"), loop length(I5㎜, 20㎜), loop configuration (open loop, closed loop), gabling (non -gable, gable). So, the total 256 specimens were divided into 32 groups, and each of those was pulled on Instron testing machine. The load-deflection curve of each wire was obtained, from which force, range in elastic limit, and stiffness were computed and analyzed statistically. The results were obtained as follows : 1. All of the variable factors-wire material, size, loop length, loop configuration, and gabling-took a significant effect on load-deflection rate of looped wire. 2. The force at elastic limit was the smallest in the group of Hi-T, .016"×.022", 20㎜ loop length, open loop, non-gable, and the largest in the group of blue Elgiloy, .018"×.025", 15㎜ loop length, closed loop, non-gable. 3. The range at elastic limit was the samllest in the group of Hi-T, .018"×.025", 15㎜ loop length, open loop, non-gable, and the largest in the group of Hi-T, .016"×.022, 20㎜ loop length, closed loop, gable. 4. Loop configuration and loop length were the most effective factors on the elastic properties of looped wires, and gabling was the least effective.

변환요소에 따른 LOOPED WIRE의 탄성 변화에 관한 연구

나용인,김상철 대한치과교정학회 1995 대한치과교정학회지 Vol.25 No.3

Canine retraction spring과 같은 looped wire에서, 각 변환요소에 따라 변하는 탄성 정도를 알아보기 위하여, wire의 재료, 굵기, loop에 소요된 길이, loop의 모양, gabling의 여부 등 5가지의 변환요소를 설정하여, 각 wire activation시의 탄성을 range, force, stiffness등의 면에서 알아보고자 하였다. wire의 재료적인 면에서 Hi-T (Unitek Co.)와 blue Elgiloy (Rocky Mountain Orthodontics)를 선택하였으며, 굵기로는 .016˝x .022˝와 .018˝x .025˝를 선택하였다. loop 자체에 소요된 wire 길이를 15mm와 20mm의 두가지로, loop의 모양을 vertical open loop과 vertical closed loop의 두가지로, gabling의 양을 0˚와 30˚의 두가지로 하여 각각 제작하였다. 따라서 wire의 재료와 굵기, loop의 길이와 모양, gabling의 5가지 변환요소에 따라 32개군으로 구분되었으며, 각 군의 시료수는 8개씩으로, 총 256개의 시료를 대상으로 하였다. Instron(4202, Instron Co, USA)을 사용하여 각 시료의 하중변형곡선을 얻었으며 elastic limit에서의 하중과 변형을 계측하고, 그때의 stiffness(force/range)를 산출하여, ANOVA 등의 통계처리로 32개군 간의 상관성을 조사하였다. 그 결과 wire의 재료, 굵기, loop의 길이, 모양, gabling 모두가 looped wire의 하중 변형도에 유의한 영향을 미치는 것을 관찰할 수 있었으며, 탄성범위에서의 force는 Hi-T, .016˝x .022˝, loop 길이 20mm, open loop, non-gable군에서 가장 적었으며, blue Elgiloy, .018˝x .025˝, loop 길이 15mm, closed loop, non-gable군에서 가장 컸다. 탄성범위에서의 range는 Hi-T, .018˝x .025˝, loop 길이 15mm, open loop, non-gable군이 가장 적었으며, Hi-T, .016˝x .022˝, loop 길이 20mm, closed loop, gable군에서 가장 컸다. 또한 Looped wire의 탄성에 가장 큰 영향을 미치는 변환요소는 loop의 모양과 길이였으며, gabling의 영향이 가장 적었다. The purpose of this study was to evaluate and compare the effect of the variable factors of wire on the elastic properties of looped rectangular wire. Five variable factors were presented - material(Hi-T, blue Elgiloy), wire size(016˝x .022˝, .018˝x .025˝), loop length(15mm, 20mm), loop configuration(open loop, closed loop), gabling (non-gable, gable). So, the total 256 specimens were divided into 32 groups, and each of those was pulled on Instron testing machine. The load-deflection curve of each wire was obtained, from which force, range in elastic limit, and stiffness were computed and analyzed statistically. The results were obtained as follows : 1. All of the variable factors - wire material, size, loop length, loop configuration, and gabling - took a significant effect on load-deflection rate of looped wire. 2. The force at elastic limit was the smallest in the group of Hi-T, 016˝x.022˝, 20mm loop length, open loop, non-gable, and the largest in the group of blue Elgiloy, .018˝x.025˝, 15mm loop length, closed loop, non-gable. 3. The range at elastic limit was the smallest in the group of Hi-T, .018˝x.025˝, 15mm loop length, open loop, non-gable, and the largest in the group of HI-T, 016˝x.022˝, 20mm loop length, closed loop, gable. 4. Loop configuration and loop length were most effective factors on the elastic properties of looped wires, and gabling was the least effective.

客家與風水文化

나용 김혜정 한국중국문화학회 2007 中國學論叢 Vol.23 No.-

이동통신망에서 이중영역 거리기준 위치등록의 성능 분석

서재준,나용,백장현,Suh, Jae-Joon,Luo, Yong,Baek, Jang-Hyun 한국시뮬레이션학회 2008 한국시뮬레이션학회 논문지 Vol.17 No.4

In this study, an improved scheme for distance-based registration (DBR) is proposed and its performance is analyzed. In the DBR, when a mobile station (MS) enters a new cell, it calculates the distance between last registered cell and current cell and registers its location if the distance reaches reference distance D. In this study, two-location DBR (TDBR) is proposed to improve the performance of the DBR. In the TDBR, an MS stores not only last registered location area (LA) but also previously registered LA, and then no registration is needed when the MS crosses two LAs stored already. However, since the TDBR may increase paging cost, trade-off is necessary between decreased registration cost and increased paging cost. In this study, the performances of two schemes are analyzed and compared using 2-dimensional random walk mobility model in hexagonal cell configuration. We show that our mathematical analysis is accurate by comparing with simulation. From the numerical results for various circumstances, it is shown that our proposed TDBR outperforms current DBR in most cases. 본 연구에서는 거리기준 위치등록(Distance-Based Registration, DBR) 방법의 성능 개선 방안을 제안하고 그 성능을 분석한다. DBR 방법에서는 이동국이 새로운 셀에 진입할 때마다 현재 셀에서 가장 최근에 위치등록한 셀까지의 거리를 계산하여, 그 값이 기준거리 D 이상이면 위치등록을 수행하게 된다. 본 연구에서는 기존DBR 방법의 성능을 개선하기 위하여 2개의 위치영역을 가질 수 있는 이중영역 거리기준 위치등록(Two-Location Distance-Based Registration, TDBR) 방법을 제안하였다. TDBR에서는 이동국이 가장 최근에 위치등록한 위치영역뿐만 아니라 그 직전에 위치등록한 위치영역까지도 저장하게 되며 이 경우 저장된2개 위치영역을 넘나들 때는 위치등록이 필요 없게 된다. 반면에 페이징 부하는 DBR보다 증가하게 되므로 줄어드는 위치등록 부하와 늘어나는 페이징 부하의 절충이 필요하게 된다.본 연구에서는 육각형 셀 환경 하에서2차원 랜덤워크 모형에 기반을 둔 이동성 모형을 이용하여 두 위치등록 방법의 성능을 분석하고 비교하였다. 시뮬레이션과의 비교를 통하여 수리적 분석이 정확함을 보였으며, 다양한 환경에 대한 수리적 결과로부터 제안하는 TDBR 방법이 기존의 DBR 방법보다 대부분의 경우 성능이 우수함을 알 수 있었다.