• 한국군사과학기술학회지
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• 제11권1호
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• pp.25-32
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• 2008

In this paper, we propose how to efficiently apply IP and TDL(Tactical Datalink) protocol to the Link-K network for using their applications on the host system. We classify 3 kinds of communication method between IP network and TDL network. We explain the concepts of Like-to-Like communication (Link-K over IP, IP over Link-K) and Any-to-Any communication. We describe the characteristics and the implementation range of tactical datalink processor for each communication method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권8호
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• pp.3766-3788
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• 2017

A blockchain is an underlying technology and basic infrastructure of the Bitcoin system. At present, blockchains and their applications are developing rapidly. However, the basic research of blockchain technology is still in the early stages. The efficiency and reliability of blockchain communication is one of the research problems that urgently need to be studied and addressed. Existing algorithms may be less feasible for blockchain-based communication because they only consider a single communication factor (node communication capability or node trust degree) and only focus on a single communication performance parameter(communication time or communication reliability). In this paper, to shorten the validation time of blockchain transactions and improve the reliability of blockchain-based communication, we first establish a multi-link concurrent communication model based on trust degree, and then we propose a novel integrated factor communication tree algorithm (IFT). This algorithm comprehensively considers the node communication link number and the node trust degree and selects several nodes with powerful communication capacity and high trust as the communication sources to improve the concurrency and communication efficiency. Simulation results indicate that the IFT algorithm outperforms existing algorithms. A blockchain communication routing scheme based on the IFT algorithm can increase communication efficiency by ensuring communication reliability.

• 한국철도학회논문집
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• 제6권2호
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• pp.135-141
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• 2003

According to the computerization of railway signaling systems, the interface link between these signaling equipment is also replaced by digital communication channel, expecially communication link for interface between EIS and LDTS, but there are some problems in the present state of railway signaling. First of all, different communication protocol is applied to interface between above two signaling equipment although they have same functions. The other is that the communication protocol currently used in railway field has some unreasonable points such as structure, formation of byte, error correction scheme and etc. To solve these problems, the standard communication protocol for railway signaling is designed. The structure of designed communication protocol and the results of performance analyses are represented in this paper. It will be expected the increase of safety, reliability and efficiency of maintenance of signaling system by using of the designed communication protocol for railway signaling.

• 한국시뮬레이션학회논문지
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• 제13권2호
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• pp.53-63
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• 2004

In ad hoc networks, the link survivability is firstly considered if a routing between two mobile nodes takes place through wireless environments, because all of mobile nodes participating in a connection dynamically move to anywhere. Also, mobile nodes have multi-role to implement a communication without a static system supported by wired networks. Hence, it is difficult that all mobile nodes continuously provide a reliable connection when the nodes operate each role for the connection. Therefore, it is desired to maximize the lifetime of a route as long as possible for the reliable communication. In this paper, we propose a proactive link management scheme that can provide the continuous route supported by the link handover. It consider the wireless link quality and the power lifetime of a node so that the link handover is implemented for the link survivability without disconnecting the route on the communication.

• 한국전자통신학회논문지
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• 제15권3호
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• pp.457-464
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• 2020

한국군은 Link-11, Link-16 과 Link-K를 적용한 한국형 전술 데이터링크 체계 JTDLS(: Joint Tactical Data Link System)를 운용하고 있다. Link-11에서 Link-22로의 교체 시점이 도래함에 따라 JTDLS 완성형 사업에서는 기존의 전술 데이터링크 외에 Link-22 등의 전술 데이터링크 처리가 추가될 예정이다. 다양한 전술 데이터링크 메시지 처리를 위해 본 논문에서는 Link-K, Link-16, KVMF 등 다중 전술 데이터링크의 데이터를 처리 할 수 있는 데이터 관리 구조를 제안하고, DLP 측면에서 많은 데이터를 빠르게 처리하는 방안을 찾기 위한 Shared Memory, In-Memory DB, 자체개발 DB를 이용하여 모의시험을 진행하고, 그 결과를 확인해 보고자 한다.

• Ocean Systems Engineering
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• 제8권1호
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• pp.33-39
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• 2018

The paper presents a numerical underwater channel model developed in MATLAB for estimating the optical link budget between a light emitting diode (LED) based optical transmitter and a photo diode (PD) receiver when operated in the harbor, coastal and deep waters locations in the Bay of Bengal. The water samples are collected at different locations in the Bay of Bengal using a water sampler during an offshore research cruise. The optical attenuation, the main inherent parameter determining the range of the optical communication link is identified for the different waters using an underwater irradiance measurement system in the laboratory. The identified parameters are applied to the numerical model and found that a 10 W LED and a photo diode based system can provide the optical budget required for a horizontal underwater communication range of about 0.5, 14 and 35 m in the harbor, coastal and deep waters locations respectively. By increasing the transmitter power to 50 W, the operating range of the communication link could be increased up to 53 m in deep water locations in the Bay of Bengal.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.85-87
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• 2012

본 논문에서는 무인항공기의 보조통신링크에 적용하는 시분할 통신방식을 분석하고, 제시된 통신 방식의 알고리즘을 개발하였다. 무인항공기의 데이터링크의 중요한 특성은 지연시간 및 데이터 전송량, 주파수 가용성, 중량이다. 무인항공기에 운용에 필요한 데이터에는 비행체제어데이터, 상태데이터, 획득 데이터가 존재한다. 제어데이터와 획득 데이터는 실시간 통신을 요구한다. 요구사항을 기반으로 보조통신링크에 적용되고 있는 통신방식을 비교 분석하였다. 분석을 한 결과 지상 기반의 시분할 통신방식이 적합하다.

• Journal of electromagnetic engineering and science
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• 제16권2호
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• pp.80-86
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• 2016

This paper proposes the algorithm for forward link adaptive coding and modulation (ACM) and the detailed design for a satellite communication system to improve network reliability and system throughput. In the ACM scheme, the coding and modulation schemes are changed by as much as the channel can provide depending on the quality of the communication link. To implement the forward link ACM system in the Ka-band, channel prediction and modulation/coding decision methods are proposed and simulated. The parameters of the adaptive filter predictor based on the least mean square are optimized, the minimum mean square error of the channel predictor is 0.0608 when step size and the number of filter tap are 0.0001 and 4, respectively. A test-bed is set up to verify the forward link ACM system, and a test is performed using a Ka-band satellite (i.e., Communication, Ocean, and Meteorological Satellite [COMS]). This test verifies that the ACM scheme can increase the system throughput.

• Journal of Positioning, Navigation, and Timing
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• 제9권2호
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• pp.139-147
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• 2020

In this paper, design measure were proposed for the construction of terminal systems for airborne platforms, which are key element in the Joint Tactical Data Link System (JTDLS) complete system. The Korean perfect tactical data link (JTDLS) is a communication system to establish an independent tactical data link network and needs to develop a MIDS-LVT (Link-16) communication terminal for datalink. Once a Ground/Navy JTDLS terminal system is established around airborne platform, it will be possible to break away from reliance on NATO-based tactical data link joint operations and establish independent Korean surveillance reconnaissance real-time data sharing and tactical data link operations concepts. in this paper, the essential development elements of airborne platform mounting and operable JTDLS terminals are presented, and the concept of system design is proposed to embody them. Further, improved system performance was analyzed by applying the concepts of complex relative navigation system and Advanced TDMA protocol for the deployment of airborne tactical datalink networks.

• Journal of Astronomy and Space Sciences
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• 제17권2호
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• pp.257-266
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• 2000

A satellite RF communication link is analyzed based on a simple fundamental equations by systematic approach in this paper. The number of variables related to a design and analysis of satellite RF link is often a dozen or more, thus it is a tedious and time-consuming task. With the given input data, the important parameters are calculated step by step and three communication characteristics such as communication channel capacity, carrier-to-noise ratio(CNR) at the satellite and ground station are analyzed. It gives very useful information to the system engineers for designing and analyzing the overall satellite communication system in the conceptual design phase.