• Title/Summary/Keyword: data link

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Implementation of Tactical Data Link System of Helicopters-Ground Units Using SEF (SEP를 이용한 헬기와 지상부대간의 전술데이터링크 체계 구현)

  • Jeong, Jae-Hyeong;Gwon, Tae-Hwan;Gwon, Yong-Su
    • 시스템엔지니어링워크숍
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    • s.4
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    • pp.146-150
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    • 2004
  • The Tactical Data Link System(TDLS) is a standardized communication link to exchange and interface positional, situational information, command and control in real time. It has been evaluated that the link would play an important role for tactical interoperability, situation awareness, and execution of joint operations in the future war. This work presents how to embody the TDLS through the systems engineering approach on the base of TDLS operating concept analysis of helicopters-groud units.

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Worker Strength-kinetic Model Analysis (작업자 체력의 Isometric Biomechanical 모델 설계)

  • Park, Myeong Kyu
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.14 no.24
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    • pp.71-81
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    • 1991
  • 인체의 운동은 많은 수의 자유도를 지닌 조인트(JOINT)와 링(LINK)의 복잡한 운동으로 표현될 수 있다. 이들 링크(LINK)의 회전 운동은 SINE, COSINE 자승 형태의 비선형 운동으로 이루어져있으나, 최근 PERSONAL COMPUTER의 발달로 복잡한 인체 운동의 수학적 모델에 대한 동력학적 DATA 계산이 가능해졌다. 본 연구에서는 5개의 링크(LINK)로 연결된 인체 움직임에 있어 링크(LINK)의 절대 운동(ABSOLUTE MOTION) 및 상대운동(RELATIVE MOTION)을 고려한 PLAGENHOEF의 운동 모델을 PERSONAL COMPUTER를 이용하여 인체 움직임의 동력학적 DATA를 얻을 수 있도록 BASIC 언어로 프로그램을 제기하였다.

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Analysis of Data Rate on Optical Communication Links between Geo-Satellite and Earth Station (정지궤도 위성과 지구국간 광통신 링크의 전송속도 해석)

  • Han, Jong-Seok;Jung, Jin-Ho;Kim, Yung-Kwon
    • Journal of IKEEE
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    • v.1 no.1 s.1
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    • pp.120-137
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    • 1997
  • Han's model, which is able to analyze optical communication between earth station and geo-satellite as a function of atmospheric conditions and elevation angles. is presented. In Han's model, atmospheric conditions are roughly classified into six basic types; clear sky, cloud, haze, fog, rain and snow. Data rate satisfying for the BER below $10^{-7}$ is analyzed by Han's model in case of up-link and down-link, respectively. Data rate is more limited by up-link than by down-link because the pointing loss caused by atmosphere on the up-link is greater than the spatial coherence degradation caused by atmosphere on the down-link.

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Tactical Data Link Message Packing Scheme for Imagery Air Operations (이미지 항공작전을 위한 전술데이터링크 메시지 패킹 기법)

  • Kim, Young-Goo;Lim, Jae-Sung;Noh, Houng-Jun;Lee, Kyu-Man
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.4B
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    • pp.278-287
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    • 2012
  • In this paper, we propose an allocation scheme for variable message packings to increase efficiency of military operation using Link-16 which is well-known for tactical data link by delivering imagery information rapidly. We propose a variable message packing scheme using COC waveform to support variable data rate under some coverage limitation. Variety of message packing makes Link-16 vary transmission rate appropriately for tactical environment. We also propose a allocation scheme to assign message packing to time slot properly. Finally we verify the performance and superiority of proposed ideas by simulations.

Unmanned aircraft that are optimized for communication method and algorithm development of secondary links (무인항공기에 최적화된 보조 링크의 통신 방식 및 알고리즘 개발)

  • Choi, Jun-Su;Hur, Chang-Wu
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.05a
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    • pp.85-87
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    • 2012
  • This paper, UAVs of the secondary communication link that applies to the analysys of time-division communication system and communication method proposed algorithm has been developed. UAVs of the important characteristics of the data link latency and throughput, the frequency is availability, weight. The data needed to operate UAVs vehicle control data, status data, there is an acquisition. Control and data acquisition will require real-time communication. Based on the requirements being applied to the secondary communication link communication method were compared and analyzed. The results of analysis of ground-base TDD method is suitable.

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Development of Link Cost Function using Neural Network Concept in Sensor Network

  • Lim, Yu-Jin;Kang, Sang-Gil
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.1
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    • pp.141-156
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    • 2011
  • In this paper we develop a link cost function for data delivery in sensor network. Usually most conventional methods determine the optimal coefficients in the cost function without considering the surrounding environment of the node such as the wireless propagation environment or the topological environment. Due to this reason, there are limitations to improve the quality of data delivery such as data delivery ratio and delay of data delivery. To solve this problem, we derive a new cost function using the concept of Partially Connected Neural Network (PCNN) which is modeled according to the input types whether inputs are correlated or uncorrelated. The correlated inputs are connected to the hidden layer of the PCNN in a coupled fashion but the uncoupled inputs are in an uncoupled fashion. We also propose the training technique for finding an optimal weight vector in the link cost function. The link cost function is trained to the direction that the packet transmission success ratio of each node maximizes. In the experimental section, we show that our method outperforms other conventional methods in terms of the quality of data delivery and the energy efficiency.

1-hop Data Traffic Reduction Method in Tactical Wireless Mobile Ad-Hoc Network based on MIL-STD-188-220C (MIL-STD-188-220C 기반 전술 무선 이동 Ad-Hoc 망에서 1-hop내 데이터 트래픽 감소 방법)

  • You, Ji-Sang
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.1
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    • pp.15-24
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    • 2008
  • The data delivery confirmation method of MIL-STD-188-220C, which is a tactical wireless mobile Ad-Hoc communication protocol, is that a source node requires the end-to-end ack from all destination nodes and the data-link ack from 1-hop neighboring destination nodes and relaying nodes, regardless of the hop distance from a source node to destination nodes. This method has the problem to degrade the whole communication network performance because of excessive data traffic due to the duplicate use of end-to-end ack and data-link ack, and the collision among end-to-end acks on the wireless network in the case of confirming a data delivery within an 1-hop distance. In order to solve this problem, this paper has proposed the method to perform the data delivery confirmation with the improvement of communication network performance through the data traffic reduction by achieving the reliable data delivery confirmation requiring the only data-link ack within an 1-hop distance. The effects of the proposed method are analyzed in the two aspects of the data delivery confirmation delay time and the data delivery confirmation success ratio.

High Speed Serial Link Transmitter Using 4-PAM Signaling (4-PAM signaling을 이용한 high speed serial link transmitter)

  • Jeong, Ji-Kyung;Lee, Jeong-Jun;Burm, Jin-Wook;Jeong, Young-Han
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.11
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    • pp.84-91
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    • 2009
  • A high speed serial link transmitter using multi-level signaling is proposed. To achieve high data rate m high speed serial link, 4-pulse amplitude modulation (PAM) is used. By transmitting 2 bit data in each symbol time, high speed data transmission, two times than binary signaling, is achieved. The transmitter transmits current-mode output instead of voltage-mode output Current-mode output is much faster than voltage-mode output, so higher data transmission is available by increasing switching speed of driver. $2^5-1$ pseudo-random bit sequence (PRBS) generator is contained to perform built-in self test (BIST). The 4-PAM transmitter is designed in Dongbu HiTek $0.18{\mu}m$ CMOS technology and achieves 8 Gb/s, 160 mV of eye height with 1.8 V supply voltage. The transmitter consumes only 98 mW for 8 Gb/s transmission.

Optical Wireless Access Point Agent Networks

  • Lee, Tae-Gyu
    • Journal of the Optical Society of Korea
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    • v.13 no.1
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    • pp.98-106
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    • 2009
  • This paper proposes an optical wireless transfer agent method which realizes the continuous and swift data transfer of optical wireless terminals in optical wireless networks. The unguided wireless channel generally shows frequent link disconnections and propagation delays due to weak wireless links. Specially speaking, optical wireless channels have more vulnerable links and roaming propagation delays relative to the weakness of the previous RF channels due to their low signal connectivity and small geographic coverage. Conventional optical wireless network protocols did not consider any fault models about physical link faults. Consequently, they have shown data transfer inefficiency for both data link control and physical wireless link control. To overcome these optical wireless environmental problems, this paper suggests a new wireless access point (or base station) agent system, which provides wireless or mobile clients with previous link layer protocols compensated.

Group-Based Frequency Hopping Scheme for Improving Multi-Net Performance of Link-16 Waveform with Limited Frequency Band (제한된 주파수 대역에서 Link-16 웨이브폼의 멀티넷 성능 향상을 위한 그룹 기반의 주파수 도약 방식)

  • Yu, Jepung;Lee, Kyuman;Baek, Hoki;Lim, Jaesung;Kim, Jongsung;Choi, Hyogi
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.1
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    • pp.110-121
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    • 2016
  • Link-16 is a representative TDL operated by US air force and NATO and supports structure of Multi-net. Under Multi-net, military operation can be conducted effectively since terminal nodes in Link-16 hop over total frequency band simultaneously. As air traffic is rapidly increasing, new aeronautical system is introduced or existing system should be expanded to accommodate increasing air traffic and frequency band assigned for operating this system is scarce. It is scheduled to implement frequency remapping to solve frequency scarcity. With limited frequency band for operating Link-16, as frequency remapping is implemented, degradation of Multi-net performance can happen since multiple access interference in Link-16 is increasing so it is difficult to conduct multiple military operations. Thus, Group-based frequency hopping scheme is proposed to solve this problem. We verified the performance of the proposed scheme is improved.