• 전자공학회논문지
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• 제50권12호
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• pp.14-21
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• 2013

위성 운용 및 우주 탐사 미션에서 레인징은 우주 항행체의 위치 정보를 얻기 위한 가장 필수적인 기술이다. 최근에 우주 탐사 미션의 정교한 수행을 위하여 우주 개발국들 간의 상호 협력의 중요성이 증대되고 있다. 상호 협력을 위하여 우주 개발국간의 상호 호환성을 가지는 레인징 시스템이 요구된다. 이러한 이유로, CCSDS는 디지털 표준 레인징 시스템으로서 의사 잡음 레인징을 권고하고 있다. CCSDS 표준 레인징 시스템에서의 의사 잡음 시퀀스의 길이는 심우주 미션에 적합하며 지구 근접 미션에 적용하기는 매우 길다. 본 논문에서는 저궤도 위성, 중궤도 위성 그리고 정지궤도 위성과 같은 지구 근접 미션에 적합한 짧은 길이의 의사 잡음 레인징 시퀀스를 제안하고, CCSDS 표준 의사 잡음 레인징 시스템을 포함하는 다중임무 수행에 적합한 가변길이 의사 잡음 레인징 시스템을 제안한다.

• Strategy21
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• 통권39호
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• pp.163-197
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• 2016

The completion of Jeju Naval Base on February 2016 made the Republic of Korea Navy(ROKN) review the size and role of the Maritime Task Flotilla(MTF). The new strategic environment for the 12st century and the new challenges require the Navy to counter North Korea's provocations and prevent potential enemy's threat. The Navy is also required to take part in the variety of international roles and missions commensurated with Korea's global status to maximize the national interest. Despite these changes, Korea's military construction concept is still unable to break away from the old paradigm of the North Korean threat largely centered. In order to develop the current MTF into the Task Group with the construction of Jeju Naval Base, the Navy must newly not only establish new force development plan and fleet management concepts but also go to persuade and convince policy decision makers. To this end, the following efforts should be promoted. First, the ROK Navy steps up efforts in order to share with the Task Group's vision and strategy. The Navy should also provide the size and structure as well as the missions and roles of the Task Group to react to new maritime security environment. Second, the Navy analyse the MTF's ability and what is required and necessary to perform its duty. After that, it must set out the direction of the Task Group's force development. Third, the current missions and roles of the MTF should be re-established to respond various threats. Finally, accommodating of new technology to the MTF should intensify its strengths. The ROK Navy has a mixed force structure consisting of three fixed- base fleets and a MTF. The fixed base fleet has a passive force to defend and protect its own sea areas, but the MTF should actively not only counter North Korea's threats, including ballistic missiles, but also fight potential threats and takes international missions as a primary task force. However, the MTF has a limited capability to accomplish given missions and long-range operations, and thus, the ROK Navy is strongly required to construct the Task Group.

• International Journal of Aeronautical and Space Sciences
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• 제18권3호
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• pp.545-554
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• 2017

Among various applications of the High Altitude Long Endurance (HALE) Unmanned Aerial Vehicle (UAV), this paper has a focus on the Global Positioning System (GPS) utilizing pseudolite and its improved performance, particularly during the multi-purpose missions. In a multi-purpose mission, the HALE UAV follows a specified flight trajectory for both navigation applications and missions. Some of the representative HALE missions are remote exploration, surveillance, reconnaissance, and communication relay. During these operations, the HALE UAV can also be an additional positioning signal source as it broadcast signals using pseudolite. The pseudolite signal can improve the availability, accuracy, and reliability of the GPS particularly in areas with poor signal reception, such as shadowed regions between tall buildings. The improvement in performance of navigation is validated through simulations of multi-purpose missions of the solar-powered HALE UAV in an urban canyon. The simulation includes UAV trajectory generation at stratosphere and uses actual geographical building data. The results indicate that the pseudolite-equipped HALE UAV has the potential to enhance the performance of the satellite navigation system in navigationally degraded regions even during multi-purpose operations.

• 한국항공우주학회지
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• 제47권9호
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• pp.678-685
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• 2019

미래 전장 환경의 변화와 항공무기체계의 기술적 발전에 따라 유인기와 무인기의 상호 보완적인 유무인기 복합 운용을 통한 임무 수행이 요구된다. 기존의 유무인기 전투체계는 항공작전임무에 따라 운용되었으며 유무인기의 성능에 따라 수행 가능한 임무가 제한된다. 본 논문에서는 유무인기 협업 기반의 임무 도출을 위해 미 국방성의 무인기 시스템 로드맵과 공군의 항공작전을 분석한 후 기존의 유무인기의 임무를 분석한다. 다음으로 임무를 수행하기 위해 필요한 유무인기의 기본 기능을 식별하고 유무인기 협업 기반의 임무를 적 방공제압 임무로 선정한 후 이 임무를 수행하기 위한 절차를 단계별로 분석한다. 본 논문은 유무인기 복합 운용 개념의 구체화를 위해 임무 단계별 절차를 물리적인 공간 및 시간 순서의 맥락으로 분석하여 제안한다.

• 천문학회보
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• 제46권2호
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• pp.62.1-62.1
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• 2021

Interstellar objects originate from other stellar systems. Thus, they contain information about the stellar systems that cannot be directly explored; the information includes the formation and evolution of the stellar systems and the possibility of life. The examples observed so far are 1l/Oumuamua in 2017 and 2l/Borisov in 2019. In this talk, we present the possibility of detecting interstellar objects using the Heliospheric Imagers designed for space weather research and forecasting by observing solar wind in interplanetary space between the Sun and Earth. Because interstellar objects are unpredictable events, the detection requires observations with wide coverage in spatial and long duration in temporal. The near-real time data availability is essential for follow-up observations to study their detailed properties and future rendezvous missions. Heliospheric Imagers provide day-side observations, inaccessible by traditional astronomical observations. This will dramatically increase the temporal and spatial coverage of observations and also the probability of detecting interstellar objects visiting our solar system, together with traditional astronomical observations. We demonstrate that this is the case. We have used data taken from Solar TErrestrial RElation Observatory (STEREO)/Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) HI-1. HI-1 is off-pointed from the Sun direction by 14 degrees with 20 degrees of the field of view. Using images observed from 2007 to 2019, we have found a total of 223 small objects other than stars, galaxies, or planets, indicative of the potential capability to detect interstellar objects. The same method can be applied to the currently operating missions such as the Parker Solar Probe and Solar Orbiter and also future L5 and L4 missions. Since the data can be analyzed in near-real time due to the space weather purposes, more detailed properties can be analyzed by follow-up observations in ground and space, and also future rendezvous missions. We discuss future possible rendezvous missions at the end of this talk.

• International Journal of Aeronautical and Space Sciences
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• 제13권2호
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• pp.154-169
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• 2012

This paper presents a comprehensive review of spacecraft guidance algorithms for asteroid intercept and rendezvous missions. Classical proportional navigation (PN) guidance is reviewed first, followed by pulsed PN guidance, augmented PN guidance, predictive feedback guidance, Lambert guidance, and other guidance laws based on orbit perturbation theory. Optimal feedback guidance laws satisfying various terminal constraints are also discussed. Finally, the zero-effort-velocity (ZEV) error, analogous to the well-known zero-effort-miss (ZEM) distance, is introduced, leading to a generalized ZEM/ZEV guidance law. These various feedback guidance laws can be easily applied to real asteroid intercept and rendezvous missions. However, differing mission requirements and spacecraft capabilities will require continued research on terminal-phase guidance laws.

• 항공우주산업기술동향
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• 제8권1호
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• pp.33-44
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• 2010

이 논문에서는 지구관측용 위성에 장착된 마이크로파 센서들의 검보정법에 대해 조사, 기술하였다. 아울러 현재 운영 중이거나 이러한 미션들을 대체하여 향후 진행될 대표적인 지구관측 미션들을 소개하였다. 보다 효과적인 이해를 위해 지구 관측 미션들을 중심으로 이들 위성에 장착된 마이크로파 센서들의 검보정법을 설명하면서, 센서들의 중요한 특징들과 주요 임무에 대해서 요약 정리하였다.

• ETRI Journal
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• 제27권4호
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• pp.394-404
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• 2005

We discuss some typical procedures to measure the efficiency of telecommand authentication systems in space missions. As a case-study, the Packet Telecommand Standard used by the European Space Agency is considered. It is shown that, although acceptable under well consolidated evaluation suites, the standard presents some flaws particularly in regard to the randomness level of the pre-signature. For this reason, some possible changes are proposed and evaluated that should be able to improve performance, even reducing the on-board elaboration time.

• 시스템엔지니어링학술지
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• 제18권1호
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• pp.14-32
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• 2022

In this paper, we report the results of a conceptual study to develop of a multi-purpose medium-sized UAV that can safely perform missions in harsh maritime environments. In this study, we focused on developing UAVs capable of performing three maritime missions that urgently require the application of medium-sized UAVs: marine ecosystem management, ocean surveillance system, and response to marine accidents. Furthermore improvement points for the above three naval missions using medium-sized UAVs were derived in preparation for the problems of the existing mission performance. Finally, by developing and analyzing the utilization scenario of the medium-class UAV, the required performance suitable for each mission was defined and assigned to the related mission equipment, A new maritime management plan was proposed using the medium-class UAV system equipped with replaceable mission equipment.

• 산업경영시스템학회지
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• 제46권4호
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• pp.294-303
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• 2023

During wartime, the operation of engineering equipment plays a pivotal role in bolstering the combat prowess of military units. To fully harness this combat potential, it is imperative to provide efficient support precisely when and where it is needed most. While previous research has predominantly focused on optimizing equipment combinations to expedite individual mission performance, our model considers routing challenges encompassing multiple missions and temporal constraints. We implement a comprehensive analysis of potential wartime missions and developed a routing model for the operation of engineering equipment that takes into account multiple missions and their respective time windows of required start and completion time. Our approach focused on two primary objectives: maximizing overall capability and minimizing mission duration, all while adhering to a diverse set of constraints, including mission requirements, equipment availability, geographical locations, and time constraints.