• Title/Summary/Keyword: Frame Relay

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Space-Time Diversity Relaying Strategy using Cooperative Communication Technique (협력 통신 기법을 이용한 시공간 다이버시티 중계 전략)

  • Kim, Eun-Ki;Park, Noe-Yoon;Lee, Kwan-Seob;Kim, Young-Ju
    • The Journal of the Korea Contents Association
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    • v.9 no.4
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    • pp.65-71
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    • 2009
  • In this paper a new space-time diversity relaying strategy using cooperative communication technique is proposed. More than one relaying terminals are included in one cooperative group to share their state information, such as frame error rate and channel state information. The best terminals are selected to send bit information using space-time diversity relay system. An implementation for the proposed scheme is also presented using the TDMA cooperative protocol. The resulting receive signal to transmit signal ratio and computer simulation demonstrate that the proposed strategy outperforms the conventional cooperative system.

Improvement Schemes of IIC’s MIC-NET Management (정보통신부 기반망 운영개선 방안)

  • 최종호
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.5
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    • pp.1129-1133
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    • 2004
  • The MIC-NET of 3,010 circuits to process on-line business on post, insurance, finance, electromagnetic wave, and so forth has the problems on spending of bandwidth for the lack of flexibility of leased-line service band. In this paper, it is suggested to establish the efficient 3 steps conversion plan through analysis and comparison with economical efficiency on MIC-NET. The promoting policy proposed in this paper, both MIC and local post office will raise image as financial institute and provide high level service with reliability and security as distinguished government organization.

A Study on the Control Method of Hand & Automatic Operation of On-Off Wiring of an Easy Elevator (간이 엘리베이터 수.자동 개폐배선 제어방식에 관한연구)

  • Wee, Sung-Dong;Gu, Hal-Bon;Kim, Tae-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.1107-1112
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    • 2002
  • An easy elevator originated is an opened system to compare an existing equipment, and learning efficient is high as a wiring that the sequence control circuit is on and off. The structure of an equipment to be controled from the first floor to the fifth floor is constructed by a lamp to express the function of the open-close of the door according to the cage moving, to express the mechanical actuation of the forward-reverse break and motor of load and of hand-worked control component of Push-Button S/W, L/S and Relay. In order to act of the elevator function that these components connected, designed the auto program and the sequence control circuit. Consequently the process that these(1~5steps) operated the cage with an auto program of the elevator and the sequence control circuit is controled by the step of forward and reverse that the L/S1~L/S5 of sensor adjust function let posit, by the adjustable S/W1~S/W5 of PLC testing panel and the S/W1~S/W5 which installed on the transparent acryl plate of a frame. In here, improved apparatus is the learning equipment of combined use to study the principle and the technique of the originated sequence control circuit and the auto program of PLC.

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Fixed Relays for Next Generation Wireless Systems - System Concept and Performance Evaluation

  • Pabst Ralf;Esseling Norbert;Walke Bernhard H.
    • Journal of Communications and Networks
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    • v.7 no.2
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    • pp.104-114
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    • 2005
  • This work presents a concept and the related analysis of the traffic performance for a wireless broadband system based on fixed relay stations acting as wireless bridges. The analysis focuses on the important performance indicators end-to-end throughput and delay, taking into account the effects of an automated repeat request protocol. An extension to a MAC frame based access protocol like IEEE 802.11e, 802.15.3, 802.16a, and HIPERLAN2 is outlined and taken as basis for the calculations. The system is intended for both dense populated areas as an overlay to cellular radio systems and to provide wide-area broad-band coverage. The two possible deployment scenarios for both dense urban and wide-area environments are introduced. Analytical and validating simulation results are shown, proving the suitability of the proposed concept for both of the mentioned scenarios. It is established that the fixed relaying concept is well suited to substantially contribute to provide high capacity cellular broad-band radio coverage in next generation (NG) cellular wireless broadband systems.

A Study on the Wiring Control Method of Hand & Auto Operation of an Easy Elevator (간이 승강기 수·자동 배선제어방식에 관한 연구)

  • 위성동;구할본
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.4
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    • pp.351-357
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    • 2003
  • An easy learning elevator originated is opened to compare the existed teaming equipment, and it had a high studied efficiency that the sequence control circuit can open and close with the wire. The structure of equipment to be controlled from the first floor to the fifth floors is demostrated by the constructive apparatus with the lamps to express the function of the open-close of the door according to the cage moving with a mechanical actuation of the forward reverse breaker and the motor of load, and the mechanical actuation of hand-operation control components of push-button S/W and L/S and relay etc. These components let connect each other in order to control of the elevator function with the auto program and the designed sequence control circuit. Consequently the cage could go and come till 1∼5 steps with an auto program of the elevator and the sequence control circuit. The sequence control circuit is controlled by the step of forward and reverse to follow as that the sensor function of L/S1 ∼ L/S5 let posit with the control switchs of S/W1 ∼ S/W5 of PLC testing panel and switchs of S/W1 ∼ S/W5 installed on the transparent acryl plate of the frame. In here, improved apparatus is the hand-auto operation combined learning equipment to study the principle and technique of the originate sequence control circuit and the auto program of PLC.

Performance Analysis of Full-Duplex Relay Networks with Residual Self-Interference and Crosstalk

  • Liu, Guoling;Feng, Wenjiang;Zhang, Bowei;Ying, Tengda;Lu, Luran
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.10
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    • pp.4957-4976
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    • 2016
  • This paper investigates the error performance of the amplify-and-forward (AF) relaying systems in the context of full-duplex (FD) communication. In addition to the inherent self-interference (SI) due to simultaneous transmission and reception, coexistent FD terminals may cause crosstalk. In this paper, we utilize the information exchange via the crosstalk channel to construct a particular distributed space-time code (DSTC). The residual SI is also considered. Closed-form pairwise error probability (PEP) is first derived. Then we obtain the upper bound of PEP in high transmit power region to provide more insights of diversity and coding gain. The proposed DSTC scheme can attain full cooperative diversity if the variance of SI is not a function of the transmit power. The coding gain can be improved by lengthening the frame and proper power control. Feasibility and efficiency of the proposed DSTC are verified in numerical simulations.

Multi-Channel MAC Protocol Based on V2I/V2V Collaboration in VANET (VANET에서 V2I/V2V 협력 기반 멀티채널 MAC 프로토콜)

  • Heo, Sung-Man;Yoo, Sang-Jo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.1
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    • pp.96-107
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    • 2015
  • VANET technologies provide real-time traffic information for mitigating traffic jam and preventing traffic accidents, as well as in-vehicle infotainment service through Telematics/Intelligent Transportation System (ITS). Due to the rapid increasement of various requirements, the vehicle communication with a limited resource and the fixed frame architecture of the conventional techniques is limited to provide an efficient communication service. Therefore, a new flexible operation depending on the surrounding situation information is required that needs an adaptive design of the network architecture and protocol for efficiently predicting, distributing and sharing the context-aware information. In this paper, Vehicle-to-Infrastructure (V2I) based on communication between vehicle and a Road Side Units (RSU) and Vehicle-to-Vehicle (V2V) based on communication between vehicles are effectively combined in a new MAC architecture and V2I and V2V vehicles collaborate in management. As a result, many vehicles and RSU can use more efficiently the resource and send data rapidly. The simulation results show that the proposed method can achieve high resource utilization in accordance. Also we can find out the optimal transmission relay time and 2nd relay vehicle selection probability value to spread out V2V/V2I collaborative schedule message rapidly.

Weaving the realities with video in multi-media theatre centering on Schaubuhne's Hamlet and Lenea de Sombra's Amarillo (멀티미디어 공연에서 비디오를 활용한 리얼리티 구축하기 - 샤우뷔네의 <햄릿>과 리니아 드 솜브라의 <아마릴로>를 중심으로 -)

  • Choi, Young-Joo
    • Journal of Korean Theatre Studies Association
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    • no.53
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    • pp.167-202
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    • 2014
  • When video composes mise-en-scene during the performance, it reflects the aspect of contemporary image culture, where the individual as creator joins in the image culture through the device of cell phone and computer remediating the former video technology. It also closely related with the contemporary theatre culture in which 1960's and 1970's video art was weaved into the contemporary performance theatre. With these cultural background, theatre practitioners regarded media-friendly mise-en-scene as an alternative facing the cultural landscape the linear representational narrative did not correspond to the present culture. Nonetheless, it can not be ignored that video in the performance theatre is remediating its historical function: to criticize the social reality. to enrich the aesthetic or emotional reality. I focused video in the performance theatre could feature the object with the image by realizing the realtime relay, emphasizing the situation within the frame, and strengthening the reality by alluding the object as a gesutre. So I explored its two historical manuel. First, video recorded the spot, communicated the information, and arose the audience's recognition of the object to its critical function. Second, video in performance theatre could redistribute perceptual way according to the editing method like as close up, slow motion, multiple perspective, montage and collage, and transformation of the image to the aesthetic function. Reminding the historical function of video in contemporary performance theatre, I analyzed two shows, Schaubuhne's Hamlet and Lenea de Sombra's Amarillo which were introduced to Korean audiences during the 2010 Seoul Theatre Olympics. It is known to us that Ostermeir found real social reality as a text and made the play the context. In this, he used video as a vehicle to penetrate the social reality through the hero's perspective. It is also noteworthy that Ostermeir understood Hamlet's dilemma as these days' young generation's propensity. They delayed action while being involved in image culture. Besides his use of video in the piece revitalized the aesthetic function of video by hypermedial perceptual method. Amarillo combined documentary theatre method with installation, physical theatre, and video relay on the spot, and activated aesthetic function with the intermediality, its interacting co-relationship between the media. In this performance theatre, video has recorded and pursued the absent presence of the real people who died or lost in the desert. At the same time it fantasized the emotional aspect of the people at the moment of their death, which would be opaque or non prominent otherwise. As a conclusion, I found the video in contemporary performance theatre visualized the rupture between the media and perform their intermediality. It attempted to disturb the transparent immediacy to invoke the spectator's perception to the theatrical situation, to open its emotional and spiritual aspect, and to remind the realities as with Schaubuhne's Hamlet and Lenea de Sombra's Amarillo.

On Implementing and Deploying Label Distribution Protocol in MultiProtocal Label Switching Systems (MPLS시스템에서 LDP 기능 구현 및 활용 방안)

  • 김미희;이종협;이유경
    • Journal of KIISE:Information Networking
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    • v.30 no.2
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    • pp.270-281
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    • 2003
  • ETF made the RFCs of MPLS technologies for providing the QoS of ATM or Frame Relay and the flexibility&scalability of IP on the Internet services. IETF has been expanding MPLS technologies as a common control component for supporting the various switching technologies called GMPLS. Also, IETF has standardized the signaling protocols based on such technologies, such as LDP, CR-LDP and RSVP-TE. ETRI developed the MPLS system based on ATM switch in order to provide more reliable services, differentiated services and value-added services like the VPN and traffic engineering service on the Korea Public Sector network. We are planning on deploying model services and commercial services on that network. This paper explains the basic functions of LDP, design and development of LDP on our system, and compares with LDP development and operation on other MPLS systems made by Cisco, Juniper, Nortel and Riverstone. In conclusion, this paper deduces the future services and applications by LDP through these explanation and comparison.

The optimum damping retrofit for cabinet structures of NPP by μ-GA (μ-GA를 이용한 원전 캐비닛구조물의 최적감쇠보강)

  • Lee, Gye-Hee;Ha, Dong-Ho
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.1 s.41
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    • pp.1-7
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    • 2005
  • The optimal seismic retrofitting of NPP(Nuclear Power Plant) cabinet structures that contain seismic category 1 relays was studied in this paper. During earthquake event, the failure modes of relays are not appeared in form of structural failure, but are appeared in form of contact chatter of relay. Therefore, the retrofitting of cabinet has to be aimed at the reducing of the structural response, such as acceleration. In this study, the optimal characteristic values of dampers were searched by ${\mu}$-GA (micro-Genetic Algorithm) scheme for several installation patterns. To keep accuracy and efficiency of analysis, the structural models of cabinet were considered as a frame structure. The responses of structure were obtained inform of acceleration response spectra derived from the results of nonlinear time history analysis including damping nonlinearity. The objective function of the optimum procedure was constructed based on the maximum ratio of maximum spectral value and target GERS (General Equipment Ruggedness Spectra). The results show the good improvements of fitness for adequate retrofitting pattern. Especially, the improvements of fitness were remarkable when the values of damping exponents are low.