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Soonyoung Han,도민득,Mingeon Kim,조승연,최승겸,Hae-Jin Choi 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.12
Workpiece localization is an essential process in modern engineering that relies on three-dimensional scanning to measure shape and position. We propose a three-dimensional scanning method using stereo vision with our designed markers and a novel stitching process. Our designed marker includes a set of nine designed points in a marker which increases the measurement accuracy. In addition, sets of marker points in multiple image shots are stitched together to accurately position the markers in our stitching process. Repeatability values measured in-plane are 7.03 and 8.14 micrometers in x and y-direction, respectively. Repeatability in zdirection (out-of-plane) is 19.71 micrometers. We also validated the performance of our method by recording displacement measurement error. The average error while measuring the displacement of 1 mm was 5.90 micrometers and its standard deviation 3.08 micrometers with repeated tests.
소형 실내 와이브로 기지국을 위한 무선 파라미터 최적화
한광훈(Kwanghun Han),나민수(Minsoo Na),최영규(Youngkyu Choi),김동명(Dongmyoung Kim),최성현(Sunghyun Choi),한기영(Kiyoung Han),윤순영(Soonyoung Yoon) 한국통신학회 2008 韓國通信學會論文誌 Vol.33 No.7A
본 논문에서는 소형 와이브로 기지국을 실내에서 운용하고자 할 때 중앙 관리 서버를 통해 기지국의 무선 파라미터를 최적화하는 방법에 대해 논의한다. 운용요원에 의해 수동으로 기지국의 무선 파라미터가 설정되던 기존의 방식과는 달리, 원격 컨트롤러를 통해 자동으로 무선 파라미터들이 설정된다는 점에서 소형 와이브로 기지국은 자가 설정 기지국 (Self-Configurable Radio Access Station: SC-RAS)으로도 명명된다. 이러한 실내 SC-RAS 망을 도입하는 주된 목적이 전송 전력의 세기를 높여 건물 안에서 발생하는 음영지역 문제를 해결하기 위함이지만, 동시에 한 가지 고려해야 하는 점은 SC-RAS가 기존 와이브로 망에 미치는 신호 간섭을 최소화해야 한다는 것이다. 결과적으로 SC-RAS의 전송 전력과 주파수 (Frequency Assignment :FA)를 올바르게 선택하는 것이 매우 중요하다. 본 논문에서는 이 SC-RAS의 무선 파라미터 최적화 문제를 혼합 정수 계획법 (Mixed Integer Programming: MIP)을 이용하여 풀고, SC-RAS 설치 전과 후의 성능을 비교 및 분석한다. Compared with the existing cellular base station whose radio parameters are configured manually, the small base station named as self-configurable base station configures its radio parameters automatically by the central controller. When installing the self-configurable base station, it should be considered primarily that the seamless coverage for the target area is secured while the signal interference to the existing cellular service area must to be minimized. In order to achieve this, it is very important to select the correct radio parameters, e.g., transmission power and working frequency. In this work, we formulate and solve the optimization problem by using mixed integer programming to optimize the air parameter for the self-configurable base stations.
공유대역에서 무선 LAN과의 공존을 위한 IEEE 802.16 WMAN의 MAC 프로토콜
한호성(Ho Seong Han),이승형(Seung Hyong Rhee),박수원(Suwon Park),한기영(Kiyoung Han),강현구(Hyongoo Kang),윤순영(Soonyoung Yoon) 한국정보과학회 2010 정보과학회논문지 : 정보통신 Vol.37 No.2
본 논문에서는 IEEE 802.11 WLAN과 IEEE 802.16 WMAN 무선 네트워크가 같은 공간에서 공유대역(shared band)을 사용하는 상황에서 공존이 가능하도록 802.16 MAC 프로토콜의 수정을 제안한다. 제안하는 WMAN MAC 프로토콜은 WLAN을 고려하여 BS(Base Station)와 SS(Subscriber Station)가 통신할 때 WLAN의 통신을 지연시켜 충돌을 피하는 방식으로 동작한다. 즉, BS에서 SS로 데이터를 전송하는 하향 서브 프레임(downlink subframe)에서는 SS가 할당받은 버스트(burst) 구간에서 CTS(Clear To Send)를 사용하여 WLAN의 전송을 막고, SS에서 BS로 데이터를 전송하는 상향 서브 프레임(uplink subframe)에서는 BS가 CTS를 사용하여 WLAN의 통신을 지연시킨다. 제안하는 프로토콜은 WLAN과의 충돌을 방지하여 전송효율을 높일 수 있으며, 이를 시뮬레이션에 의해 분석한다. In this paper, we propose to modify the IEEE 802.16 MAC protocol in order to allow the coexistence of IEEE 802.11 and IEEE 802.16 wireless networks in shared bands. Our suggested protocol enables 802.16 WMAN to control WLAN devices for the coexistence. That is, in the downlink subframes(BS to SS), SS(Subscriber Station) prohibits WLAN to transmit by using CTS(Clear to Send) in order to protect it's burst. In the uplink subframes(SS to BS), on the other hand, BS(Base Station) sends CTS to block WLAN's communications. Our proposals enables the coexistence between WLAN and WMAN, and simulation results show that our protocols enhance the throughput of the entire system.
( Han-suk Kim ),( Ho Young Jo ),( Soonyoung Yu ),( Yong-sung Joo ),( Man Jae Kwon ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2
In order to elucidate the relationship among biogeochemical properties, microbial communities and the potential for affecting the fate of contaminants in subsurface environments, high-resolution site characterization (HRSC) research was performed in a test-bed site (100 m × 60 m) formerly used as a farm land for several decades. Total 72 soil samples were collected from three depths (10-40, 80-110, and 160-190 cm). The results of 16S rRNA gene sequencing showed that 68 different phylum-level lineages were present in soils. Microbial diversity in soils significantly decreased with depth. Chloroflexi and Firmicutes increased with depth, while Proteobacteria, Plantomycetes and Nitrospirae decreased with depth. The shared genera at three depths only accounted for 8% of the bacterial community suggesting that each soil layer contained distinct microbial communities. The results also well correlated with toxic metal concentrations and other physical and chemical properties in soils. Water content, As, Ni, total Cr and Pb, significantly increased with depth, but soil pH, bacterial population, total carbon, nitrate, Cd, Cu, Zn and bioavailable iron (0.5N HCl extractable iron) decreased with depth. In addition, XRF analysis indicated that the concentrations of Ca, K, S, and P were higher at the top soil layer and decreased with depth. The results suggest that the distinct micrbial communities and their associated metabolic activity in three soil layers at the site are tightly linked to the physical and geochemical variables, and subsequently influences on the distribution of metals and nitrate.