• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.6
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• pp.520-527
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• 2013

In this paper, a joint cell grouping and user association technique proposed for a semi-dynamic grouped network MIMO in a clustered heterogeneous cellular network (HCN). With the conventional macro BSs, small cells are being overlaid to increase a spectral efficiency per area and these small cells are expected to be concentrated to support exponentially increasing data traffic in hot spot areas. The main culprits of performance degradation in the clustered HCN are interference and load imbalance. The proposed scheme jointly handles them to maximize a proportional-fair metric. It is shown that the proposed technique can largely improve user average rate and proportional fairness among users than any other conventional schemes in the clustered HCN.

• Journal of the Korean Chemical Society
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• v.49 no.1
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• pp.7-15
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• 2005

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.139-143
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• 2021

본 논문에서는 꾸준히 연구되어 오던 이미지 복원 문제에서 초해상화와 인페인팅이라는 복합적 이미지 복원을 동시에 처리하는 해결 방법을 제안한다. 초해상화는 국지적 픽셀 정보를 이용하여 고해상도의 영상을 복원하고, 인페인팅은 이미지 전체 정보를 활용하여 영상 내 비어 있는 영역을 생성해야 하므로, 이러한 두 가지 영상 복원 기법을 동시에 수행하는 것은 상당히 어려운 문제이다. 그렇기에 인페인팅과 초해상화는 이미지 복원에서 널리 활용되는 기술인 만큼 동시에 해결할 수 있는 기법에 대한 수요는 있음에도 지금까지 거의 연구되지 않았다. 본 논문은 초해상화 및 인페인팅 합동 처리에 있어 복합적인 정보를 모두 다뤄야하는 네트워크가 서로의 성능을 저하시키지 않도록 개략적 복원 네트워크 (Coarse network), 디테일 복원 네트워크 (Refinement network), 초해상화 네트워크 (SR network)로 분리하여 초해상화 및 인페인팅 합동 처리를 수행하며, 각 단계마다 결과 영상을 얻어 스케일 별 정답 영상과 손실함수를 계산하여 복합적인 성능을 올릴 수 있는 방법을 제시한다. 또한 순차적 단일 모델에 비하여 인페인팅과 초해상화를 합동 학습하는 제안 모델이 개선된 화질의 결과 영상을 획득할 수 있다는 것을 실험적으로 보인다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.379-382
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• 2021

합동 해안경계시스템은 해상경계시스템과 해안대침투경계시스템으로 구성되며 주로 해군이 해상경계를, 육군이 해안경계를 책임지고 있는 시스템이다. 해군 및 육군의 다양한 무기체계가 복합적으로 운용되는 해안경계시스템의 작전효과를 시뮬레이션 기법을 이용하여 분석하였다. 작전효과 분석을 통해 현재 운용중인 해안경계시스템의 기상상태별 작전성공률 계량화가 가능하였다. 연구결과는 효과적인 합동 해안경계시스템을 구축하고 체계적인 경계작전을 수행하는데 활용될 수 있다.

• Journal of Information Technology and Architecture
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• v.11 no.1
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• pp.11-23
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• 2014

Kill Chain is getting attention due to North Korea's recent nuclear test and missile launches and has emerged the need for an early build up. In order to build a materialized kill chain, you should review the unique kill chain to support operations effectively using various sensors and striking weapon system. Especially, you need a suitable network to reduce a reaction time against the enemy attack under joint operations environment etc. Currently there are many communication ways(e.g. data link, voice, video and text message) used in operations through satellite, wired and wireless and so on. Now, this paper contains analysis on various means for target information exchange which are used in the kill chain. And appropriate network of the kill chain for target information transmission is addressed to confirm feasibility of its alternatives, which is developed using AHP(Analytic Hierarchy Process). Finally, this paper is suggesting network and means of its building up for target information transmission of kill chain which can be implemented under the situation of joint battle field.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.5
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• pp.458-465
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• 2011

UAV-UGV teaming concept has been proposed that can compensate for weak points of each platform by providing carrying, launching, recovery and recharging capability for the VTOL-UAV through the host UGV. The teaming concept can expand the observation envelop of the UGV and extend the operational capability of the UAV through mechanical combination of each system. The spherical-shaped coaxial rotorcraft UAV is suggested to provide flexible and precise interface between two systems. Hybrid navigation solution that included vision-based target tracking method for precision landing is investigated and its experimental study is performed. Feasibility study on length-variable rotor to provide the compact configuration of the loaded rotorcraft platform is also described.

• Proceedings of the Korea Society for Simulation Conference
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• 2000.04a
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• pp.153-153
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• 2000

최근 선진국들은 신규 워게임모형 개발시 장차전 개념을 반영하기 위하여 미래전자의 주요기능인 C4ISR 및 객체지향 기법을 적용하려고 노력하고 있다. 이러한 워게임 모형들은 현실과 같은 가상환경에서 합동작전을 모의할 수 있으며 전략, 작전 및 전술 수준을 모두 고려할 수 있고 지상전, 공중전, 해상전, 미사일전, 정보전 등 현대 전투개념을 모두 반영할 수 있도록 초대형 시뮬레이션 시스템으로 발전되고 있다. 본 고에서는 C4I 기능통합 및 연동화 모의 논리중에서 전략기동, 전술기동, 교전평가, 전략수송, 표적탐색, 미사일 판정을 위한 모의 기법과 초대형 시뮬레이션 시스템의 자료/명령 전달 구조 및 하드웨어/소프트웨어 사양, 구성 모듈등을 분석한다. 특히 현재 미 합참에서 개발중인 JWARS모형의 주요 객체들인 전투공간개체(BSE: Battle Space Entity), 아크-노드 네트워크, 화력 집중점(FCPs: Fire Concentration Points) 등을 살펴보고 현대전의 가장 큰 특징인 C4ISR/(Command, Control, Communication, Computer, Intelligence, Surveillance, Reconnaissance) 분야에서 표적탐지, 통신, 정보 모의 기법을 분석함으로써, 향후 한국적 여건에 적합한 분석모형 개발 방향을 제시하고자 한다.

• Korean Journal of Construction Engineering and Management
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• v.24 no.2
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• pp.98-110
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• 2023

The smart city public and private partnership project is a project to build and operate a sustainable city by investing land and capital in public-private partnership to build urban infrastructure and providing various urban services. It highly depends on the precise feasibility study and the projection of the various factors affecting the project during the planning stage to get the project successful. However, it is very difficult to predict the possibility of the project success in advance due to various physical and social factors. It is necessary to derive factors affecting the project at the planning stage and respond with appropriate analysis in order to solve these problems and to carry out a successful project. Therefore, this study derived preliminary components for feasibility study through previous studies and order status analysis and presented feasibility study components such as five-step processes, 10 process items, 19 analysis items, and 54 detailed analysis items through the Delphi method. It can be expected that this research is to contribute corresponding to diversified possible risks and facilitate the projects during the promotion.

• Journal of The Korean Institute of Defense Technology
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• v.5 no.3
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• pp.8-17
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• 2023

The current weapon system is operated as a complex weapon system with various standards and protocols applied, so there is a risk of failure in smooth information exchange during combined and joint operations on the battlefield. The interoperability of weapon systems to carry out precise strikes on key targets through rapid situational judgment between weapon systems is a key element in the conduct of war. Since the Korean military went into service, there has been a need to change the configuration and improve performance of a large number of software and hardware, but there is no verification system for the impact on interoperability, and there are no related test tools and facilities. In addition, during combined and joint training, errors frequently occur during use after arbitrarily changing the detailed operation method and software of the weapon/power support system. Therefore, periodic verification of interoperability between weapon systems is necessary. To solve this problem, rather than having people schedule an evaluation period and conduct the evaluation once, AI should continuously evaluate the interoperability between weapons and power support systems 24 hours a day to advance warfighting capabilities. To solve these problems, To this end, preliminary research was conducted to improve defense interoperability capabilities by applying natural language processing techniques (①Word2Vec model, ②FastText model, ③Swivel model) (using published algorithms and source code). Based on the results of this experiment, we would like to present a methodology (automated evaluation of interoperability requirements evaluation / level measurement through natural language processing model) to implement an automated defense interoperability evaluation tool without relying on humans.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.10
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• pp.881-891
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• 2017

In this paper, we described the new TLE(Two Line Elements) generation method based on the compansation technique by using past TLEs(Two Line Elements) released by JSpOC(Joint Space Operation Center) in USA to reduce the orbit prediction error for long duration of SGP4(Simplified General Perturbations 4) which is a simplifed and analytical orbit propagator. The orbital residuals the orbital difference between two ephemeris for the first TLE only and for the all TLEs updated by JSpOC for the past some period was applied for this algorithm instead of general orbit determination software. Actually, in these orbital residuals, the trend of orbit prediction error from SGP4 is included. Thus, it is possible to make a simple residual function from these orbital residulas by using the fitting process. By using these residual functions with SGP4 prediction data for the currnet TLE data, the compansated orbit prediction can be reconstructed and the orbit prediction error for long duration of SGP4 is also reduced. And it is possible to generate new TLE data from it. In this paper, we demonstraed this algorithm in simple simulation, and the orbital error is decreased dramatically from 4km for the SGP4 propagation to 2km for it during 7 days as a result.