차세대 이동통신서비스에서 트래픽 모델 변화에 따른 국내 주파수 소요량 및 무선 네트워크 자원 산출 방법에 관한 연구

정우기,홍인기 한국항행학회 2003 韓國航行學會論文誌 Vol.7 No.2

ITU-R. 권고안에서는 현재 및 미래 이동통신서비스의 주파수 소요량을 산출하는 일반적인 방법론을 제시하고 주파수 소요량 산출을 위한 12가지 파라미터를 권고하였다. 본 논문에서는 ITU가 제시한 12가지 파라미터에 대해 분석하여 국내 고유 파라미터 산출 방식과 파라미터 값을 제시하였고, 분석한 값을 적용하여 2010년경 국내 이동통신 서비스를 위한 무선 네트워크 자원과 주파수 소요량을 산출하였다. 또한 주파수 소요량 산출 파라미터의 변화에 따라 주파수 소요량 크기를 산출하여 향후 이동통신 서비스의 발전 추세에 따른 주파수 소요량의 변화를 분석하였다. ITU-R recommends general methodology to provide current and future mobile communication services and 12 parameters to calculate terrestrial spectrum requirements. In this paper we analyzed 12 parameters suggested by ITU-R Recommendation and provided a method to determine a specific parameter value in a specific region. We calculated spectrum requirements and network resources for year 2010 in Korean mobile environment by applying parameter values acquired in parameter analysis method of this paper. And we analyzed the variation of spectrum requirements by calculation spectrum requirements depending on variation of parameters for future mobile communication services.

Calculation of Spectral Efficiency for Estimating Spectrum Requirements of IMT-Advanced in Korean Mobile Communication Environments

Woo-Ghee Chung,박한규,Euntaek Lim,Jong-Gwan Yook 한국전자통신연구원 2007 ETRI Journal Vol.29 No.2

In this paper, we analyze the algorithm of the methodology developed by ITU for the calculation of spectrum requirements of IMT-Advanced. We propose an approach to estimate user density using traffic statistics, and to estimate spectrum efficiencies using carrier-to-interference ratio distribution and capacity theory as well as experimental data under Korean mobile communication environments. We calculate the IMT-Advanced spectrum requirements based on the user density and spectral efficiencies acquired from the new method. In the case of spectral efficiency using higher modulation and coding schemes, the spectrum requirement of IMT-Advanced is approximately 2700 MHz. When applying a 2×2 multiple-input multiple-output (MIMO) antenna system, it is approximately 1500 MHz; when applying a 4×4 MIMO antenna system, it is approximately 1050 MHz. Considering that the development of new technology will increase spectrum efficiency in the future, the spectrum requirement of IMT-Advanced in the Korean mobile communication environment is expected to be approximately 1 GHz bandwidth.

5G 이동통신 서비스를 위한 효율적인 5G 망구축 방안에 관한 연구

정우기(CHUNG, Woo-Ghee) 한국전자파학회 2018 한국전자파학회논문지 Vol.29 No.5

본 논문에서는 5G 이동통신의 서비스 트래픽 특성 및 주파수를 분석하고, 5G 이동통신 서비스를 효율적으로 제공할 수 있는 망구축 및 운용 방안을 제시하였다. 5G 이동통신 서비스는 수 kbps의 음성 및 사물인터넷 서비스부터 1 Gbps 이상의 홀로그램 영상 서비스까지 다양한 데이터 전송 속도를 나타내고 있다. 5G 이동통신 서비스는 다양한 데이터 전송 속도와 모바일 서비스 트래픽의 증가로 인한 다중 주파수 대역을 이용함으로써 다양한 셀 커버리지 환경을 나타낸다. 5G 이동통신 서비스를 효율적으로 제공하기 위해서는 새로운 서비스 환경에서 나타나는 서비스 커버리지와 다중대역 주파수의 최적화된 망구축이 필요하다. 현재 논의되는 5G 주파수 블록을 고려하여 3.5 GHz 대역이 5G 서비스 100 Mbps를 셀 경계 200 m에서 제공한다고 가정하면, 28 GHz 대역은 1 Gbps의 홀로그램 서비스를 셀 경계 50 m에서 그리고 500 Mbps 4k UHD 서비스를 셀 경계 100 m에서 제공할 수 있음을 보여주고 있다. 따라서 다양한 5G 서비스를 다중 주파수 대역과 매칭하는 주파수 포트폴리오를 구성한 망구축 방안은 5G 이동통신 서비스를 효율적으로 제공할 수 있다. We herein analyze the service traffic characteristics and spectrum of the 5G mobile communication and suggest the effective 5G network deployment method for 5G mobile communication services. The data rates of the 5G mobile communication are from several kbps (voice and IoT) up to 1 Gbps (hologram, among others). The 5G mobile communication services show the diverse cell coverage environments owing to the use of diverse service data rates and multiple spectrum bands. To effectively support the 5G mobile communication services, the network deployment requires the optimization of the service coverages for new service environments and multiple spectrum bands. Considering the 5G spectrum bandwidth debated at present, if the 5G services of 100 Mbps can be supported in the 200 m cell edge using the 3.5 GHz spectrum bands, the 5G services of the 1 Gbps hologram and 500-Mbps 4k UHD can be supported in the cell edges of 50 m and 100 m using the 28 GHz spectrum bands. Therefore, the 5G services can be supported effectively by the 5G network deployment using spectrum portfolio configurations to match the diverse 5G services and multiple bands.

국내 이동 통신 트래픽 분석에 의한 3G 이동 통신 주파수 소요량 산출

정우기(Woo-Ghee Chung) 한국전자파학회 2009 한국전자파학회논문지 Vol.20 No.3

최근 국내의 3G 서비스가 본격적인 성장 단계로 들어섬에 따라 트래픽 증가율에 따른 주파수 소요량 변화가 매우 커지고 있다. 따라서 이동 통신 주파수의 재분배가 활발히 검토되고 있는데 우선적으로 정확한 주파수 소요량 산출 방법이 요구된다. 그러나 기존 산출 방법은 현재의 실질적인 데이터 분석보다 미래의 서비스 예측에 의존하고 있다. 본 논문에서는 실질적인 데이터 분석에 의한 보다 정확한 주파수 소요량 산출 방법을 제시하기 위해 국내 3G 이동 통신 서비스의 실제 트래픽 특성 및 3G 이동 통신 서비스용 주파수 소요량 산출에 알맞은 알고리즘을 분석하고, 주파수 소요량 산출에 필요한 파라미터를 구하였다. 2007년말 실제 트래픽 파라미터에 근거하여 향후 4년간 데이터 트래픽이 각각 매년 44 % 및 매년 21 %씩 증가하는 경우에 따른 주파수 소요량을 산출하였다. 주파수 소요량 산출 결과는 2011년말까지 매년 44 % 증가하는 경우 약 90 ㎒, 매년 21 % 증가하는 경우 약 60 ㎒로 나타났다. Recently, as the 3G services of Korea have stepped into the developing stage and the traffic has been rapidly increasing, the spectrum requirements have been getting very large. Therefore spectrum refarming is considered actively and firstly exact methodology of spectrum requirement estimation is needed. But existing methodology depends on the future's service forecast than the present substantial data. This paper proposed the exact methodology of spectrum requirement estimation is based on the real data. So this paper analyzed the characteristics of Korean mobile communication traffic based on the real data and the algorithm suitable for estimation of spectrum requirements for 3G mobile communications, and calculated the parameters needed to estimate the spectrum requirements. Based on the traffic parameters of December 2007, simulations to get the estimation of annual spectrum requirements were implemented for the two different cases: one of which is 44 % annual increase in the data traffic and the other is 21 % annual increase. The simulation results show 90 ㎒ for the first case and 60 ㎒ for the second case in December 2011.

Involvement of p53-Mediated Mitochondrial Stress in the Apoptosis Induced byFlavonoids Purified from Rhus verniciflua Stokes in Human Osteosarcoma Cells

Song-Woo Chung,Seung-Ah Lee,Jong-Sun Park,Kwon-Woo Ryu,Mun-Ju Jang,Song-Soo Park,Choon-Bong Lee,Jong-Ghee Kim,Young-Mi Jeon,Jeong-Chae Lee 한국생약학회 2007 Natural Product Sciences Vol.13 No.1

flavonoids have antioxidant and antitumor promoting efects. Rhus verniciflua Stokes (RVS)is a flavonoid-rich herbal medicine and has long been used as a food additive and an antitumor agent in Korea.Previous study demonstrated that a purified flavonoid fraction prepared from RVS, herein named RCMF (theRVS chloroform-methanol fraction), exhibited growth inhibition and induced apoptosis in human osteosarcoma(HOS) cells. This study evaluated if p53-mediated pathway is asociated with the RCMF-induced apoptosis inincreased p53 expression in the cells. However, the RCMF-induced cytotoxicity was suppressed by transfectingthe cells with antisense p53 oligonucleotide, which also inhibited the decrease of Bcl-2 and the increase of Bax inmitochondria, and the release of cytochrome c into cytosol. This finding suggests that p53-mediated mitochondrialstress is required for RCMF-induced apoptosis in HOS cells.Keywordsflavonoids, human osteosarcoma cells, apoptosis, p53, mitochondrial stress

하악골 후퇴 수술 환자의 연조직 측모 예측의 정확성 : Quick Ceph Image Pro™(ver 3.0)와 V-Ceph™(ver 3.5)의 비교 a comparison of Quick Cept Image Pro™(ver 3.0) and V-Ceph™(ver 3.5)

김명규,최용성,정송우,전영미,김정기 대한치과교정학회 2005 대한치과교정학회지 Vol.35 No.3

본 연구는 Quick Ceph Image Pro^(™)(ver 3.0)와 국내에서 개발되어 사용 중인 V-Ceph (ver. 3.5) 2 종의 비디오 이미지 예측 프로그램의 수술 후 연조직 측모의 정확성과 신뢰성에 대해서 알아보고자 시행되었다. 골격성 Ⅲ급 부정교합으로 진단되어 수술 전 교정 치료를 받고, 하악골 후퇴 수술(body osteotomy 또는 SSRO)을 시행한 남녀 환자 각각 20명을 대상으로 하였다. 나이는 평균 21.4 ± 4세이고, 수술 전 측모두부방사선계측사진은 수술 전 평균 21.1일에, 수술 후 측모두부방사선계측사진은 수술 후 평균 335.7일에 촬영되었으며, 예측치와 실측치 차이를 비교하였다. 연구결과 Quick Ceph과 V-Ceph 모두 예측치와 실측치 사이에 크기와 방향에 있어서 오차가 관찰되었으며 이러한 오차는 상순과 하순, 턱과 연관된 항목에서 크게 나타났다 (p〈0.05). Quick Ceph은 A', Ls, Li의 수평적 위치 및 각 부분에서의 연조직 두께(Ul-Ls, L1-Li, Pog-Pog')의 수평거리 예측에서,Y-Ceph은 하순의 수직적 위치 예측에서 오차가 컸다 (p〈0.05) V-Ceph의 경우 하악골의 이동양이 증가할 때 Sn의 수직적 위치, Ls의 수평적 위치, 상순의 연조직 두께(U1 -Ls)처럼 상순과 연관된 계측치에서 예측오차가 컸으며, Quick Ceph의 경우 하악골의 이동양이 증가할 때 하순의 수평위치 및 하순의 두께에서의 예측오차가 작았다 (p〈0.05). 또한, 연조직의 두께에 따른 오차를 평가한 결과, Quick Ceph의 경우 상순과 하순의 두께가 두꺼울수록 각각에 관련된 연조직 예측의 오차가 컸으며 (p〈0.05), Y-Ceph의 경우 하순과 턱의 연조직 두께가 두꺼울수록 턱의 연조직 예측의 오차가 크게 관찰되었다 (p〈0.05). 그러나, 본 연구에서의 모든 예측오차값은 3 mm 이내로 계측되었으며 이러한 오차 범주는 임상적으로 허용 가능한 수준인 것으로 생각된다. The purpose of this study was to test and compare the accuracy and reliability of soft tissue profile predictions generated from two computer software programs (Quick Ceph Image Pro^(™) (ver 3.0) and V-Ceph^(™) (ver 3.5)) for mandibular set-back surgery. The presurgical and postsurgical lateral cephalograms of 40 patients (20 males and 20 females) were traced on the same acetate paper with the reference taken as the cranial base outline. The presurgical skeletal outlines were digitized onto each computer program and the mandible was moved to mimic the expected surgical procedure with reference to the mandibular anterior border and lower incisor position of the actual postsurgical skeletal outline. The soft tissue profile was generated and the amount and direction of skeletal movement was calculated with each software. The predicted soft tissue profile was compared to the actual postsurgical soft tissue profile. There were differences between the actual and the predicted surgical soft tissue profile changes in the magnitude and direction, especially the upper lip, lower lip and the soft tissue chin (p〈0.05). Quick Ceph had more horizontal measurement errors and thickness errors for the upper lip and lower lip, but V-Ceph had more vertical measurement errors of the lower lip (p〈0.05). There was a positive correlation between the prediction errors and the amount of mandibular movements in the vertical position of Sn, the horizontal position of Ls and the upper lip thickness for V-Ceph, and there was a negative correlation in the horizontal position and the thickness of the lower lip for Quick Ceph (p〈0.05). However, all of the prediction errors of both imaging softwares were ranged within 3 mm, and this was considered to be allowable clinically.

Comparison of Early and Late Conversion of Sirolimus in Experimental Model of Chronic Cyclosporine Nephropathy

Kim, Jin Young,Ghee, Jung Yeon,Lim, Sun Woo,Piao, Shang Guo,Chung, Byung Ha,Yoon, Hye Eun,Hwang, Hyeon Seok,Choi, Bum Soon,Kim, Jin,Yang, Chul Woo The Korean Academy of Medical Sciences 2012 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.27 No.2

<P>Sirolimus (SRL) is a promising drug for replacing calcineurin inhibitors. We performed this study to determine the optimal time of conversion from cyclosporine (CsA) to SRL in an experimental model of chronic CsA nephropathy. Three separate studies were performed. In the first study, SRL was given to rats with or without CsA for 4 weeks. In the second study, rats were treated initially with CsA for 1 week, and then switched to SRL (early conversion). In the third study, CsA was given for 4 weeks and then replaced by SRL for 4 weeks treatment of CsA (late conversion). The influence of SRL on CsA-induced renal injury was evaluated by assessing renal function, histopathology (interstitial inflammation and fibrosis), and apoptotic cell death. Combined CsA and SRL treatment significantly impaired renal function, increased apoptosis, and interstitial fibrosis and inflammation compared with CsA or SRL treatment alone. Early conversion to SRL did not change renal function, histopathology, or apoptosis compared with early CsA withdrawal. By contrast, late conversion to SRL significantly aggravated these parameters compared with late CsA withdrawal. In conclusion, early conversion from CsA to SRL is effective in preventing CsA-induced renal injury in a setting of CsA-induced renal injury.</P>

Spectrum Requirements for the Future Development of IMT-2000 and Systems Beyond IMT-2000

Yoon Hyun-Goo,Chung Woo-Ghee,Jo Han-Shin,Lim Jae-Woo,Yook Jong-Gwan,Park Han-Kyu The Korea Institute of Information and Commucation 2006 Journal of communications and networks Vol.8 No.2

In this paper, the algorithm of a methodology for the calculation of spectrum requirements was implemented. As well, the influence of traffic distribution ratio among radio access technology groups, spectral efficiency, and flexible spectrum usage (FSU) margin was analyzed in terms of the spectrum requirements, with a view toward for future development of international mobile telecommunication (IMT)-2000 and systems beyond IMT-2000. The calculated spectrum requirement in the maximum spectral efficiency case is reduced by approximately 40% compared to a minimum spectral efficiency case. The effect of the distribution ratio on the required spectrum is smaller than the effect of the spectral efficiency. As the flexible spectrum usage margin increases by 1.0 dB, the total spectrum requirement decreases by 0.9 dB. The required spectrum for the market input parameter, ${\rho}$ = 0.5 is 801.63 MHz, while the required spectrum for ${\rho}$ = 1.0 is 6295.4 MHz. This is equivalent to an increase of 785.32 %.

Accelerating Effects of Quercetin on the TNF-α-Induced Apoptosis in MC3T3-E1 Osteoblastic Cells

Yong-Sung Choi,Song-Woo Chung,Young-Mi Jeon,Jong-Ghee Kim,이정채 한국생약학회 2005 Natural Product Sciences Vol.11 No.3

Bioflavone quercetin is believed to play an important role preventing bone loss by afectingosteoclastogenesis and regulating many systemic and local factors including hormones and cytokines. This studyexamined how quercetin acts on tumor necrosis factor-alpha (TNF-α)-mediated apoptosis in MC3T3-E1osteoblastic cells. Apoptosis assays revealed the dose-dependent acceleration of quercetin on TNF-α-inducedapoptosis in MC3T3-E1 cells, which was demonstrated by the increased number of positively stained cells in thetrypan blue staining and TUNEL assay, and the migration of many cells to the sub-G0/G1 phase in flow cytometricanalysis. In particular, quercetin treatment alone increased the expresion of p53 and p21 proteins in the cells.Consequently, this study showed that quercetin accelerates the TNF-α-induced apoptosis in MC3T3-E1osteoblastic cells.

4세대 이동통신 서비스 주파수 소요량에 관한 연구

정우기,윤현구,임재우,육종관,박한규,Chung Woo-Ghee,Yoon Hyun-Goo,Lim Jae-Woo,Yook Jong-Gwan,Park Han-Kyu 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.2

본 논문에서는 4세대 이동통신 주파수 소요량 산출 방법론을 구현하고, 주파수 소요량의 변화에 큰 영향을 미치는 RATG간 트래픽 배분을, 주파수 효율성, FSU 이득과 시장 데이터 입력 파라미터 ${\rho}$에 따른 주파수 소요량의 변화를 시뮬레이션 하였다. 트래픽 배분율에 따른 주파수 소요량 변화는 $1\;GHz/20\;\%$정도였으며, 주파수 효율성에 따른 변화는 $5{\sim}9\;GHz$였다. 그리고 FSU 이득이 1 dB 증가하면 주파수 소요량은 약 0.9 dB 정도 감소하였다. 시장 데이터 입력 파라미터 ${\rho}=0.5$ 일 때 주파수 소요량은 801.63 MHz, ${\rho}=1.0$ 일 때는 6295.4 MHz로, 시장 데이터 입력 파라미터가 주파수 소요량에 미치는 영향이 가장 크다. In this paper the algorithm of a methodology for the calculation of spectrum requirements was implemented. As well, the influence of traffic distribution ratio among radio access technology groups, spectral efficiency, and flexible spectrum usage(FSU) margin was analyzed in terms of the spectrum requirements, with a view toward for future development of IMT-2000 and systems beyond IMT-2000. The ratio of the spectrum requirement to the traffic distribution ratio is approximately $1\;GHz/20\;\%$, and the spectrum requirement varies from 5 to 9 GHz. As the FSU margin increases by 1.0 dB, the total spectrum requirement decreases by 0.9 dB. The required spectrum for the market input parameter, ${\rho}=0.5$ is 801.63 MHz, while the required spectrum for ${\rho}=1.0$ is 6295.4 MHz. It can be concluded that the market input parameter is the most effective parameter in the calculation of spectrum requirements.