DSR 라우팅 프로토콜을 사용한 Ad-hoc 무선망에서의 TCP 성능 분석

박승섭,육동철,Park, Seung-Seob,Yuk, Dong-Cheol 한국정보처리학회 2002 정보처리학회논문지 C : 정보통신,정보보안 Vol.9 No.5

Ad-hoc 무선망은 통신을 지원하는 베이스 스테이션과 같은 기반 구조를 가지지 않는 이동 노드들로만 구성된 망이다. 그러므로 노드의 이동으로 인해 Ad-hoc 무선망의 토폴로지가 자주 변하며, 이에 따른 패킷의 손실이 발생한다. 본 논문에서는 대표적인 On-Demand Ad-hoc 라우팅 알고리즘인 DSR 프로토콜을 사용하는 Ad-hoc 무선망에 TCP Tahoe, Sack, Reno 버전을 각각 적용하여, 망의 크기의 변화와 이동 노드의 속도의 변화에 따라 트래픽의 성능을 모의 실험하여 비교 분석하였다 모의 실험 결과로, TCP Reno가 TCP Tahoe와 Sack 버전 보다 높은 처리율을 보였으며, 노드의 이동 속도와 망의 크기에 민감하지 않으므로 성능이 상대적으로 안정적이라는 것을 알 수 있었다. Ad-hoc networks consist of a set of mobile hosts that communicate using wireless links, without the use of other supporting communication facilities (such as base stations, etc.). Therefore, the topology of an Ad-hoc network frequently changes due to the movement of mobile host, which nay lead to sudden packet loss. Recently, the large amount of research has focused on the routing protocols needed in such an environment. In this paper, TCP Reno, Sack, and Tahoe versions are analysed using DSR protocol which is the representative On-Demand routing protocol in Ad-hoc wireless network. As the result of this simulation, we know that TCP Reno relatively has higher throughput than that of Sack and Tahoe, and TCP Reno has more stable performance than that of TCP Tahoe and Sack, regardless of the speed of mobile node and the size of topology.

단일 구동파형을 적용한 AC PDP에서 방전 안정성 강화를 위한 비대칭 전극의 시뮬레이션

박승섭(Seung Seob Park),조병권(Byung-Gwon Cho) 한국정보기술학회 2017 한국정보기술학회논문지 Vol.15 No.4

In the AC PDP, if the driving waveform is applied to only the other two electrodes while one electrode of the top plate is grounded among the three electrodes, the cost was lowered because the number of parts of the driving circuit can be reduced. However, when this drive waveform was applied to the conventional panel structure, an misfiring discharge occurred during the sustain period. Since the misfiring discharge during the sustain period is generated between the scan electrode of the upper plate and the address electrode of the lower plate, it is possible to prevent the misfiring discharge by applying the additional voltage to the address electrode during the time when the positive voltage is applied. On the other hand, a panel having an asymmetric electrode structure in which the width of the scan electrode in the top plate is reduced compared to other electrodes is proposed because continuous application of the address voltage during the sustain period causes power loss of the drive circuit and shortening the life of the component, and it was confirmed that the misfiring discharge did not occur in the asymmetric electrode structure using the discharge and wall charge simulations.

상판 전극들 사이에 먼 거리를 갖는 교류형 플라즈마 디스플레이에서 휘도효율의 향상

박승섭(Seung Seob Park),조병권(Byung-Gwon Cho) 한국정보기술학회 2017 한국정보기술학회논문지 Vol.15 No.2

The luminance and luminance efficiency were investigated when the proposed driving waveform was applied to the AC PDP structure with the long distance between the two electrodes of the top plate under the high Xe gas mixture. Compared with the conventional structure, one electrode in the top plate is far from the other electrode, so it must be modified in the driving waveform, especially in the reset and sustain period. During the reset period, the negative voltage was applied to the sustain electrode to generate a surface discharge between the scan and sustain electrodes on the upper substrate. In addition, during the sustain period, the driving waveform was modified to induce the surface discharge between the top plates after triggering first between the electrodes of the top and bottom plates. As a result of applying a modified driving waveform with the positive sustain voltage of 140V and the negative triggering voltage of -110V during the sustain period under the panel condition in which the Xe gas content in the panel is 15% and the electrode interval of the top plate is 500μm, the luminance of 340cd/㎡ and the luminous efficiency of 3.26lm/W were obtained.

전류정보 기반의 파워 윈도우용 안티핀치 시스템의 전류 임계값 자동 설정 및 성능 분석

박승섭(Seung-Seob Park),정석권(Seok-Kwon Jeong) 한국동력기계공학회 2017 동력시스템공학회지 Vol.21 No.5

수리과학 ; ATM 통신 시스템 방식의 성능 시뮬레이션에 관한 연구

박승섭(Seung Seob Park) 부경대학교 기초과학연구소 1998 부경대 기초과학연구논문집 Vol.1 No.-

플라즈마 디스플레이 패널에서 방전의 지연시간 단축을 위한 추가 기입 전압

박승섭(Seung Seob Park),조병권(Byung-Gwon Cho) 한국정보기술학회 2017 한국정보기술학회논문지 Vol.15 No.8

In order to shorten the discharge delay time of the write period in the plasma display panel, a modified drive waveform using an additional write voltage is presented. The write time takes about 70% of the time in the PDP, but this time can be shortened if the write discharge characteristic is improved. In the conventional case, a method of preventing the wall charge loss inside the cell is prevented by applying the last voltage of the falling ramp applied to the scan electrode less than the scan voltage in the reset period. However, as the voltage difference between the ramp-down voltage and the scan voltage becomes larger, the discharge delay time is shortened. However, at a high write voltage, an misfiring discharge was occurred and a driving voltage margin was reduced. In order to overcome the limit of the breakdown voltage of the write circuit and to use a high write potential difference, we proposed a modified drive waveform in which an additional voltage level is added to the existing write voltage at the write electrode. As a result, the address discharge delay time in one pulse of the address period could be reduced about 300ns.

교류형 플라즈마 디스플레이 패널에서 양과 음의 유지 전압에 따른 수명의 연구

박승섭(Seung Seob Park),정연태(Yeon Tae Jeong),조병권(Byung-Gwon Cho) 한국정보기술학회 2020 Proceedings of KIIT Conference Vol.2020 No.10

문턱전압 폐곡선을 이용한 AC PDP에서 인가전압에 의한 기입방전 특성의 연구

박승섭(Seung Seob Park),조병권(Byung-Gwon Cho) 한국정보기술학회 2020 한국정보기술학회논문지 Vol.18 No.2

The characteristics of the write discharge in the AC plasma display panel are determined by the sum of the wall voltage and the applied voltage formed inside the cell. If the applied voltage is increased under the high wall voltage condition, since the voltage is higher than the total voltage at which the discharge is generated in the cell, the misfiring discharge occurs in the unwanted cell. Therefore, as the total voltage generated inside the cell should be the same, the method of reducing the wall voltage and increasing the applied voltage is proposed. In this study, the write discharge characteristics of the applied voltage when the applied voltage was lower than the wall voltage and high were measured. The applied and the wall voltages were measured using the threshold voltage closed curve. As a result, the write discharge time can be shortened from 1.5 to 1.15μs when the applied voltage is higher than the wall voltage.

트랜지션 메카니즘이 적용된 IPTV Network에서 PSNR을 이용한 방송화질 측정 연구

김광현,박승섭,Kim, Kwang-Hyun,Park, Seung-Seob 한국정보통신학회 2010 한국정보통신학회논문지 Vol.14 No.1

인터넷과 IP 네트워크 기술의 발전은 IPTV, VoIP와 같은 IP Network을 통한 융합화된 새로운 서비스형태를 창출하게 되었다. 특히 차세대 IP분야인 IPv6의 발전은 인터넷 사용자들의 증가로 인한 IP 주소 고갈의 문제를 해결해 줄 것이며, 보안, QoS 및 대용량의 대역폭등 높은 수준의 서비스 품질을 요구하는 IPTV Network에서는 그 중요성 매우 높아지고 있다. 본 논문에서는 IPv6 네트워크 환경 하에서 다양한 라우팅 프로토콜들에 대하여, 사용자 관점에서의 객관적 화질 평가방법인 PSNR을 이용하여 IPv6 네트워크에서 최적의 영상 품질을 서비스 할수 있는 기준을 제시하고자 한다. Development of IP network technology creates new service which applying to fusion technologies such as IPTV, VoIP, and so on. Especially, Next generation IP is called IPv6 which will solve the lack of IP. IPv6 is very important on IPTV which needs best quality of service about security, QoS, and bandwidth. In this paper, we constructed experimental network, measured PSNR which computes the peak signal-to-reconstructed video measurement in experimental network environment, analyzed PSNR value. And as a result of measurement, we, Propose optimum network environment for IPTV service provider and transition mechanism designer.

Core-Stateless망에서의 공정한 대역폭 할당 방식

김문경,박승섭,Kim Mun-Kyung,Park Seung-Seob 한국정보처리학회 2005 정보처리학회논문지 C : 정보통신,정보보안 Vol.12 No.5

공정한 전송률을 보장하고 지연을 줄이기 위해 인터넷상에서 많은 흐름단위 스케줄링 알고리즘이 제안되어졌으며, 효율성이 필요한 공정한 대역폭 할당을 위한 공정큐잉 알고리즘이 설계되었다. 그러나 흐름단위 처리를 기본으로 하는 알고리즘은 전송률 상태, 버퍼 관리, 패킷 스케줄링 등의 기능을 필요로 하며, 이와 같은 복잡성으로 인해 구현하는데 비용이 많이 드는 문제점이 있다. 따라서 본 연구는 효율적인 비용으로 라우터를 구현하기 위해, FM(Flow Number Estimation)를 기반으로 한 CS-FNE(Core Stateless FNE) 알고리즘을 제안하며, 다양한 네트웍 환경과 트래픽 소스를 사용해서 CSFQ(Core Stateless Fair Queueing), FRED(Fair Random Early Detection), RED(Random Early Detection), DRR(Dynamic Round Robin) 등과 같은 알고리즘을 CS-FNE와 함께 평가하였다. 모의 실험 결과로, 본 연구에서 제안된 방식이 다른 알고리즘보다 적절히 공정한 대역폭 할당을 나타내었으며, 흐름단위 기반 큐잉 메커니즘보다 더 단순하고, 쉽게 구현될 수 있음을 보였다. To provide the fair rate and achieve the fair bandwidth allocation, many per-flow scheduling algorithms have been proposed such as fair queueing algorithm for congestion control. But these algorithms need to maintain the state, manage buffer and schedule packets on a per-flow basis; the complexity of these functions may prevent them from being cost-effectively implemented. In this paper, therefore, to acquire cost-effectively for implementation, we propose a CS-FNE(Core Stateless FNE) algorithm that is based on FM(Flow Number Estimation), and evaluated CS-FNE scheme together with CSFQ(Core Stateless Fair Queueing), FRED(Fair Random Early Detection), RED(Random Early Detection), and DRR(Dynamic Round Robin) in several different configurations and traffic sources. Through the simulation results, we showed that CS-FNE algorithm can allocate fair bandwidth approximately than other algorithms, and CS-FNE is simpler than many per-flow basis queueing mechanisms and it can be easily implemented.