무선 AP 공유를 통한 호 제어 방안 연구

임승철,Lim, Seung-Cheol 한국인터넷방송통신학회 2018 한국인터넷방송통신학회 논문지 Vol.18 No.4

최근 인공지능기술이 보편화 되면서 무선 트래픽에 대한 수요가 급속히 늘어나고 있다. 무선 트래픽 수요의 증대에 따른 서비스를 제공하기 위해서 통신사들에서는 공중 AP 설치를 보편화 하고 있다. 각 통신사들간의 무선 AP 사용의 편리성을 제공하기 위해서 공공장소에서의 AP들의 사용을 공유하여 공공장소에서 무선자원을 효율적으로 사용하게 하고, 이동통신서비스에서 무선AP간의 사전인증방식과 핸드오프처리를 수행하여 사용자의 편리성을 증대하고자 한다. 본 논문에서는 이동통신서비스에서 AP간의 핸드오프와 통신사간의 사전인증을 통한 공공장소에서의 AP를 공유하는 것을 제안한다. 제안한 내용은 모의실험을 통하여 핸드오프 지연시간이 35.1%향상되고, 사전인증으로 통해 제안한 방식으로 AP선택해서 사용하는 대역폭이 자동으로 AP선택하는 방식보다 더 많은 대역폭을 활용할 수 있음을 확인할 수 있다. Recently, as artificial intelligence technology becomes popular, demand for wireless traffic is rapidly increasing. In order to provide services in response to the increase in demand for wireless traffic, telecommunication companies are generalizing the installation of public APs. In order to provide convenience of using wireless APs between communication companies, it is necessary to share the use of APs in public places to efficiently use wireless resources in a public place, to pre-authenticate between wireless APs in a mobile communication service, So as to increase the convenience of the user. In this paper, we propose to share APs in public places through handoff between APs and pre-authentication between carriers in mobile communication services. The simulation results show that the handoff latency is improved by 35.1% and the bandwidth used by the AP selected by the pre-authentication method can utilize more bandwidth than the method of automatically selecting the AP.

PR형 공압 머니퓰레이터의 위치서보제어

임승철,어윤범,Lim, Seung-Cheol,Eao, Yun-Beom 대한기계학회 1997 大韓機械學會論文集A Vol.21 No.10

This paper concerns a 2-axis PR type pneumatic manipulator system translating in vertical and rotating in horizontal directions. A simplified linear model is mathematically formulated similar to the pneumatic acturators in dynamic responses in order to devise an appropriate position control scheme. A PD controller preceding the on/off solenoid valve turns out not only economical but also effective in reducing rise time and amplitude of limit cycles, if its control gains are determined on the basis of frequency response. And, additional implementation of symmetric or asymmetric deadband at the PD controller output greatly helps minimize valve opening numbers, positional error, and undesirable direction-dependent property due to the gravitational load. Such a control concept is synthesized through numerical simulations and next applied to the experimental set-up, featuring enhanced positional servo characteristics.

이동통신 핸드오프 호에 대한 시스템 성능연구

임승철(Seung-Cheol Lim) 한국정보기술학회 2007 한국정보기술학회논문지 Vol.5 No.2

In this paper, we analyze the performance of system about the dwelling time at the buffer for the handoff calls in multiple cell CDMA environments, which have the non-uniform traffic load distribution and the multiple types of services. In CDMA system, the number of mobile stations which can be served simultaneously in a base station is limited by the amount of total interference received. Further, the average number of mobile stations in each cell may not be uniformly distributed. Considering the facts, the call admission control method using the effective bandwidth concept is employed in this paper. The bandwidth for a newcall and a handoff call is dynamically assigned by taking account of the blocking rate of new calls and the dropping rate of handoff calls. The handoff call not admitted dwells at buffer. The dwelling time at the buffer is assigned by three methods - constant, exponential function and consideration of velocity. The performance of system is analyzed through the simulation. From the simulation, we can know that assigning the dwell time of the buffer by the velocity of the call has the lowest dropping rate on the use a buffer for hand off call.

매크로/마이크로 셀룰러시스템에서 핸드오프용 채널 할당에 따른 시스템 성능분석

임승철(Seung-Cheol Lim) 한국정보기술학회 2008 한국정보기술학회논문지 Vol.6 No.3

In CDMA system, the number of mobile stations which can be served simultaneously in a base station is limited by the amount of total interference received. Further, the average number of mobile stations in each cell may not be uniformly distributed. Considering the facts, the call admission control method is important about new call admission control, and handoff call control scheme. This paper describes implementation of CDMA mobile system, with non reversible hierarchical and reserved handoff channels. The call allocation scheme in CDMA system for an new and handoff calls are using in Non reversible Hierarchical and Reserved Handoff Channels. Using Reserved Handoff Channels scheme, we analysis new call blocking rate and handoff call blocking in macro/micro cellular system. The results show that the blocking rate of handoff call this implementation algorithm when average call arrival time(0.1529) and reserved channel g3, is 0.03. That is lower value that of reserved channel g0.

다중 셀 시스템의 호 수락제어 방식 연구

임승철(Seung-Cheol Lim) 한국정보기술학회 2009 한국정보기술학회논문지 Vol.7 No.3

In this paper, we analyze the performance of system in multiple cell mobile environments, which have the non-uniform traffic load distribution and the multiple types of services. In mobile system, the number of mobile stations which can be served simultaneously in a base station is limited by the amount of total interference received. Further, the average number of mobile stations in each cell may not be uniformly distributed. Considering the facts, the call admission control method using the effective bandwidth concept is employed in this paper. The bandwidth for a newcall and a handoff call is dynamically assigned by taking account of the blocking rate of new calls and the dropping rate of handoff calls. The performance of system is analyzed through the simulation. From the simulation, we can know that effective bandwidth dynamic assignment more better than that of fixed assignment scheme. The system performance is about 9% upgrade.

텔레메틱스 시스템개발

임승철(Seung-Cheol Lim) 한국정보기술학회 2009 Proceedings of KIIT Conference Vol.2009 No.-

본 논문에서는 ETC 서비스를 제공하는 텔레메틱스 시스템 트래픽 제어 서비스와 장치를 개발하는 방법에 대해서 살펴보았다. 현재 국내에서는 한국도로공사에서 하이패스 서비스를 제공하고 있다. 본 논문에서는 ETC 기술과 통신방식에 대해서 연구하고 ETCS 하드웨어 시스템 구조와 선불카드와 과금처리를 위한 시스템인터페이스를 연구하였다. In this paper, ETC service implementation scheme for Telematics system is proposed for traffic control service and apparatus. Now, Hi-pass is servicing in Korea Expressway Corporation. In this paper, we discuss ETC techniques and communication techniques and research ETCS hardware system architecture and system interface specification with prepaid card implementation scheme for paying transaction. The results discuss general ETC services, providing ETC system configuration and environment.

적송잎증류농축액의 항균활성 및 항산화활성

민경철(Kyung-Cheol Min),임승철(Seung-Cheol Lim),김보경(Bo-kyung Kim),김근대(Geun-Dae Kim),김익종(Ikchon Kim),이상현(Sang-Hyeon Lee),김미향(Mihyang Kim) 한국생명과학회 2021 생명과학회지 Vol.31 No.10

본 연구에서는 적송잎증류농축액을 이용하여 그람음성 병원성 균주들에 대한 항균활성 및 항산화활성을 측정하였다. 적송잎증류농축액 에멀션의 항균활성을 paper disc법으로 측정한 결과, 그람음성 병원성 균주인 E. coli, S. typhi, V. parahaemolyticus에 대해 항균활성을 나타냈으며, 5% (v/v)의 농도에서 각각 12 mm, 10 mm, 9 mm의 생육저해환(clear zone)을 보였다. 또한, 가장 낮은 농도인 0.5% (v/v)의 농도에서도 3종의 균주 모두에서 활성을 보였다. 그러나 그람양성 병원성 균주에 대한 항균활성은 나타나지 않았다. 적송잎증류농축액의 항균활성을 비탁법으로 측정한 결과, paper disc법의 결과와 마찬가지로 그람음성 병원성 균주인 E. coli, S. typhi, V. parahaemolyticus에 대해 항균활성을 나타냈다. V. parahaemolyticus에서는 5% (v/v)의 농도에서 음성 대조군에 비해 60% 이상의 생장억제를 보였고, E. coli에서는 배양 4시간에서 64.3%, S. typhi에서는 배양 4시간과 5시간에서 각각 94.2%, 94.1%의 생장억제를 보였다. 적송잎증류농축액 에멀션의 항산화활성을 DPPH radical 소거능으로 측정 한 결과, 1.0% (v/v)의 농도에서 55.81%의 활성을 나타냈다. 적송잎증류농축액 에멀션의 항산화활성을 ABTS radical 소거능으로 측정한 결과, 1.0% (v/v)의 농도에서 18.44%의 활성을 나타냈다. 본 연구를 통해, 적송잎증류농축액의 생리활성인 항균활성 및 항산화활성을 검증하였으며, 이를 이용하여 기능성이 강화된 식품 및 화장품의 개발이 가능할 것으로 기대된다. In this study, antibacterial activity against pathogenic strains and antioxidant activity were measured using the red pine leaf distilled concentrate. The results of the antibacterial activity measured using an emulsion of the red pine leaf distilled concentrate by the paper disc method showed the antibacterial activities against three Gram negative pathogenic strains, E. coli, S. typhi and Vibrio parahaemolyticus and exhibited growth inhibitions of 12 mm, 10 mm and 9 mm at a 5.0% (v/v) concentration, respectively. In addition, all three strains also showed growth inhibitions even at 0.5% (v/v) concentration. However, no antibacterial activity was exhibited against gram positive bacteria. The results of the antibacterial activity using the red pine leaf distilled concentrate measured by the turbidity method, the same antibacterial activities against three gram negative pathogenic strains, E. coli, S. typhi and V. parahaemolyticus as results of the paper disc method. V. parahaemolyticus showed more than 50% growth inhibition compared to the negative control at a concentration of 5% (v/v), E. coli exhibited 33.5% growth inhibition at 4 hr incubation, and S. typhi showed 65.1% and 44.6% growth inhibitions at 4 and 5 hr incubations, respectively. Antioxidant activities of an emulsion of the red pine leaf distilled concentrate were measured by DPPH and ABTS methods. DPPH method showed the highest activity of 55.81% at a 1.0% (v/v) concentration. ABTS method exhibited the highest activity of 18.44% at a 1.0% (v/v) concentration. Through this study, it is expected that the developments of the food and the cosmetics with enhanced functionality by utilizing the antioxidant and antibacterial activities of the red pine leaf distilled concentrate.

TINA 기반의 도메인간 컴포지션 구조 설계

이상백(Sang-Baek Lee),임승철(Seung-Cheol Lim),박동선(Dong-Sun Park) 한국산업정보학회 1999 한국산업정보학회 학술대회논문집 Vol.1999 No.5

VSC형 퍼지 논리 제어기의 설계 방법과 등가성에 관한 연구

최병재(Byung-Jae Choi),임승철(Seung-Cheol Lim),명기환(Ki-Hwan Myung),백승철(Seung-Cheol Baek),정인수(In-Soo Jung),최동선(Dong-Sun Choi) 한국지능시스템학회 1996 한국지능시스템학회 학술발표 논문집 Vol.6 No.1

CMS 제어국 소프트웨어 구조의 설계

박영옥(Young-Ok Park),임승철(Seung-Cheol Lim),최성구(Sung-Gu Choi),권수근(Soo-Kun Kwon),안지환(Jee-Hwan Ahn) 대한전자공학회 1995 대한전자공학회 학술대회 Vol.1995 No.12