LoRa 통신망을 이용한 스마트 IoT 플랫폼 개발

권기원(Ki-Won Kwon),이해연(Hae-Yeoun Lee) 한국정보기술학회 2022 한국정보기술학회논문지 Vol.20 No.7

Although the demand for smart factory is increasing, existing factory systems consist of outdated mechanical equipments without networks and automation facilities. With the recent activation of IoT-based services, this limitations can be solved. This paper describes the development of a LoRa network-based smart IoT platform to solve the limitations of smart factory implmentation and communication in old factories. It describes the development of a multiple input/output IoT interface board for I/O with sensors and LoRa communication is explained. Also, the construction of a control server that can monitor and control sensors and analyze data is presented. Through data sending and receiving experiments on the implemented platform, it was confirmed that packets were transmitted without errors and various data could be collected and analyzed remotely to implement a smart factory.

DRM 시스템에서 초기 샘플링 주파수 옵셋의 영향에 강인한 고속 동기화 방식

권기원(Ki Won, Kwon),조용수(Yong Soo Cho) 한국통신학회 2012 韓國通信學會論文誌 Vol.37 No.1A

본 논문에서는 DRM(Digital Radio Mondiale) 수신기를 위한 고속 동기화 방식을 제안한다. 제안하는 방식에서는 DRM 수신기에서 요구하는 고속 수신 성능을 만족시키기 위해 기존 동기화 방식에서 수행하는 초기 샘플링 주파수 동기과정을 생략하고 정수배 주파수(Integer Frequency) 동기 및 프레임(Frame) 검출을 수행한 후, 추적(Tracking) 과정에서 샘플링 주파수 동기를 수행한다. 샘플링 주파수 옵셋(Sampling Frequency Offset)이 포함된 OFDM(Orthogonal Frequency Division Multiplexing) 복조 심볼로부터 프레임 옵셋을 추정하기 위해 참조셀(Reference cell)에 상관 기반 추정 알고리즘을 적용하고 그 성능을 분석하여 샘플링 주파수 옵셋에 강한 알고리즘을 선정한다. 제안된 구조는 DRM 수신 신호에 샘플링 주파수 옵셋이 존재하는 경우에도 초기 샘플링 주파수 동기화 과정에 소요되는 시간을 단축할 수 있으며, 참조셀간 차동 상관(Inter-cell Differential Correlation) 기법을 사용할 경우 초기 샘플링 주파수 옵셋의 영향에 강인함을 프레임 검출 모의실험을 통해 확인한다. In this paper, we propose a high-speed synchronization method for Digital Radio Mondiale (DRM) receivers. In order to satisfy the high-speed synchronization requirement of DRM receivers, the proposed method eliminate the initial sampling frequency synchronization process in conventional synchronization methods. In the proposed method, sampling frequency tracking is performed after integer frequency synchronization and frame synchronization. Different correlation algorithms are applied to detect the first frame of the Orthogonal Frequency Division Multiplexing (OFDM) demodulation symbol with sampling frequency offset (SFO). A frame detection algorithm that is robust to SFO is selected based on the performance analysis and simulation. Simulation results show that the proposed method reduces the time spent for initial sampling frequency synchronization even if SFO is present in the DRM signal. In addition, it is verify that inter-cell differential correlation used between reference cells is roubst to the effect of initial SFO.

WindowCE 기반 DMB 2.0 수신기 설계 및 구현

권기원(Kwon Ki Won),박용석(Park Yong Suk),김현식(Kim Hyun Sik),백종호(Parik Jong Ho) 한국통신학회 2010 한국통신학회 학술대회논문집 Vol.2010 No.6

iOS 기반 ATSC-M/H 수신기 설계 및 구현

권기원(Kwon Ki Won),박용석(Park Yong Suk),김현식(Kim Hyun Sik),백종호(Paik Jong Ho) 한국통신학회 2011 한국통신학회 학술대회논문집 Vol.2011 No.2

Information Backpropagation 학습 알고리즘을 이용한 무선 통신용 XPIC의 성능 분석

권기원(Ki-Won Kwon),양완철(Wan-Chul Yang),이병섭(Byung-Seob Lee) 한국통신학회 2001 한국통신학회 학술대회논문집 Vol.2001 No.11

임분내 광환경의 차이에 따른 주요 참나무 수종의 생장과 엽록소 함량 변화에 관한 연구

권기원(Ki-Won Kwon),최정호(Jeong-Ho Choi),송호경(Ho-Kyung Song),강병식(Byung-Sik Kang) 한국산림바이오에너지학회 2003 산림바이오에너지 Vol.22 No.3

참나무류 주요 수종을 대상으로 다양한 광선 조건에 식재된 실생묘의 활착 및 상대생장량과 광선에 대하여 민감하게 작용하는 엽록소 함량의 계절적인 변화를 조사하기 위하여 상수리나무 1-1묘, 1-0묘, 신갈나무 1-0묘, 졸참나무 1-0묘, 굴참나무 1-0묘를 상수리나무 임분내에 상층임분 밀도를 자연광의 81%, 34%, 21% 등 3가지로 조절하였다.<br/> 조사대상 수종의 묘목을 20m x 10m 크기의 시험구에 100본씩 식재하여 활착율, 상대생장량, 엽록소 함량을 비교하였다.<br/> 상수리나무 1-1묘가 평균 73%로 다른 수종에 비해 높은 활착율을 보였고, 상수리나무 1-0묘가 66%, 신갈나무와 졸참나무가 각각 56%, 45%였으며, 굴참나무는 41%로 이식후 활착율이 가장 낮게 나타났다. 또한 자연광의 81% 실험구에서 대부분의 주요 참나무류 수고, 근원경 생장이 가장 좋은 경향을 보여 주고 있었으며 자연광의 21% 실험구에서는 오히려 광도가 낮아지면서 생장이 상대적으로 저해되는 경향을 보여 주고 있다. 엽록소 함령(a, b, 총엽록소 함향)은 광도가 낮아지면서 엽록소 함량도 낮아지는 것을 알 수 있었다. 그러나 주요 참나무류 수종의 피음 효과에 대한 생장반응은 지속적으로 관찰해야 하며, 엽록소 함량과 생장에 밀접한 관련이 있는 생리적 특성에 대한 연구도 필요할 것으로 생각된다. This study was subjected to compare seasonal changes of survival rate, relative growth rate, and chlorophyll contents of major oak tree species including Quercus acctissima, Quercus mongolica, Quercus serrata, Quercus variabilis seedlings grown in Quercus acctissima forest under different light intensities. Three light intensities were 81% of sunlight, 34% of sunlight and 21% of sunlight. In each treatment, 100 tree seedlings were planted and survival rate, growth rate, and chlorophyll contents were measured. <br/> The highest survival rate was Quercus acctissima in 73% seedlings compared with those subjected to the other tree seedlings in 45~66%. Lowest survival rate was Quercus variabilis seedlings in 41%. Oaks tree species of the height, the root collar diameters of the relative growth were better in the seedlings grown in 81% light intensities of full sun. But growth rates decreased rapidly in the shade treatment of 21% light intensities of full sun. Lowest chlorophyll contents(chlorophyll a, b and total) were shown at 21% light intensities of full sun, lowest light intensity treatment in this study. This result is thought growth and chlorophyll contents associated with light intensity. Also, Physiological characteristics has to be investigated in near future because photosynthesis and chlorophyll contents were strongly related to tree growth with long periods.

멀티모드 이동 방송용 EWS(Emergency Warning System) 송ㆍ수신 시스템 설계 및 구현

권기원(Ki Won Kwon),박용석(Yong Suk Park),박세호(Se Ho Park),백종호(Jong Ho Paik) 한국통신학회 2012 韓國通信學會論文誌 Vol.37 No.12(융합기술)

본 논문은 재난 정보를 다양한 모바일방송 규격에 따라 인코딩 및 송출, 수신 및 디코딩하는 멀티모드 방송용 EWS 송ㆍ수신 시스템의 설계 및 구현 방법을 제안한다. 제안한 시스템은 전 세계 모바일 방송 표준 중 T-DMB, DVB-H, ISDB-T와 디지털 라디오 규격인 DRM을 지원하며, 각각의 방송 규격에 따라 재난 정보를 인코딩하는 송출부와 각 표준에 따른 RF 방송 신호를 수신 및 디코딩하는 수신부 형태로 구성된다. 제안한 멀티모드 방송용 EWS 송신시스템은 단일 시스템상에서 각각의 방송규격으로 EWS 재난 데이터 생성하고 상용 방송 송출 장비규격에 만족하는 채널 인터페이스를 통해 재난정보가 송출 가능하며 수신 시스템에서는 단일 H/W에서 해당 모드의 재난 정보를 수신, 디코딩하여 단말기 화면에 표출한다. 제안된 시스템은 실시간으로 각 모드별 상용 방송장비에서 송출되는 RF 신호를 수신하여 문자기반의 재난 정보를 표출하는 정합 검증 과정을 통해 정상동작 결과를 제시한다. This paper presents the design and implementation of a multi-mode mobile broadcasting Emergency Warning System (EWS) transmission and reception system which enables the propagation of disaster information using the encoding and transmission, reception and decoding methods specified in diverse mobile broadcasting standards. The implemented system supports global mobile broadcasting standards such as Terrestrial Digital Multimedia Broadcasting (T-DMB), Digital Video Broadcasting-Handheld (DVB-H), Integrated Services Digital Broadcasting-Terrestrial (ISDB-T), and the Digital Radio Mondiale (DRM) digital radio standard. The system consists of two key part: an encoding/transmission part and a reception/decoding part. The multi-mode mobile broadcasting EWS encoding and transmission system generates EWS data according to each broadcasting specification. The generated EWS data is then transmitted through a channel interface which meets the commercial broadcasting equipment specification. The receiver system receives and decodes the EWS data on a single hardware platform and can display the results on screen. Verification and conformity testing has been carried out on the implemented system by transmitting emergency data for each mode in real-time and displaying the received information in text on the receiver display.

급성 코카인 투여에 의한 흰쥐의 보행성 활동량 및 초기유전자 c-Fos 발현에 대한 건지황의 효과

권기원 ( Ki Won Kwon ),장은영 ( Eun Young Jang ),양재하 ( Chae Ha Yang ),김광중 ( Kwang Joong Kim ) 대구한의대학교 제한동의학술원 2009 東西醫學 Vol.34 No.3

DVB-T 시스템에서 잔여 주파수 오차 추정 기법

권기원(Kwon Ki Won),서정욱(Seo Jeong Wook),이연성(Lee Youn Sung),김현식(Kim Hyun Sik) 한국통신학회 2009 한국통신학회 학술대회논문집 Vol.2009 No.6

수분 및 양료 (養料) 처리에 따른 참나무류와 물푸레나무의 생장 및 생리 반응

권기원(Ki Won Kwon),이정호(Jeoung Ho Lee) 한국산림과학회 1994 한국산림과학회지 Vol.83 No.2

Temporal changes in growth performances, chlorophyll contents, and tissue water relations for determining their physiological responses of five economic tree species subjected to chronic water and nutrition stresses were investigated with containerized seedlings grown in different soil moisture regimes and nutrition levels. Seedlings of Quercus acutissima, Q. variabilis, Q. mongolica, Q. serrata, and Fraxinus rhynchophylla were propagated in plastic pots(I.D. 16㎝×Depth 16㎝) for the experiments. The seedlings were subjected to two soil moisture regimes of dry and wet soils and two nutrition levels of fertilization with N+P+K and no fertilization through the growing season from May to September in a green house. For the purpose of analyzing their responses to the environmental stresses, seedling heights and root collar diameters, chlorophyll contents, and P-V curve parameters of the seedlings were measured in May, July, and September. The environmental stresses coming from moisture and nutrient deficits affected the growth performances of seedlings variously among species and among different growing periods, as well as between height and basal diameter growth of seedlings. The growth performances of Q. acutissima were influenced sensitively on the stresses, but those of Q. mongolica less influenced in comparison with other species. Chlorophyll contents were generally higher in Quercus spp. than F. rhynchophylla through the growing season. The chlorophyll contents changed by species and by treatment through the season within ranges of 0.14-1.96 ㎎/g dry wt. of chlorophyll a and within 0.16-1.79㎎/g dry wt. of chlorophyll b, respectively. But the contents seemed to be decreased gradually through the chronic environmental stresses and leaf senescence. The osmotic potential at full turgor(Ψπo) and turgor loss point(Ψπp) had temporarily declined up to 3 to bars from -7.0∼-12.4bars in May to -10.2∼-17.5bars in September and up to 5 to 6bars from -7.6∼-14.2 bars in May to -12.9∼-20.4bars in September, respectively, with some exceptions. The values of Ψπp were generally high in F. rhynchophylla in May and July, but high in Q. serrata in September. Relative water contents at turgor loss point(RWCp) were generally high in F. rhynchophylla, but the temporal changes of RWCp were quite and frequently different among species and among treatment.