• Journal of Astronomy and Space Sciences
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• v.31 no.3
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• pp.247-264
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• 2014

In this paper, a brief but essential development strategy for the lunar orbit determination system is discussed to prepare for the future Korea's lunar missions. Prior to the discussion of this preliminary development strategy, technical models of foreign agencies for the lunar orbit determination system, tracking networks to measure the orbit, and collaborative efforts to verify system performance are reviewed in detail with a short summary of their lunar mission history. Covered foreign agencies are European Space Agency, Japan Aerospace Exploration Agency, Indian Space Research Organization and China National Space Administration. Based on the lessons from their experiences, the preliminary development strategy for Korea's future lunar orbit determination system is discussed with regard to the core technical issues of dynamic modeling, numerical integration, measurement modeling, estimation method, measurement system as well as appropriate data formatting for the interoperability among foreign agencies. Although only the preliminary development strategy has been discussed through this work, the proposed strategy will aid the Korean astronautical society while on the development phase of the future Korea's own lunar orbit determination system. Also, it is expected that further detailed system requirements or technical development strategies could be designed or established based on the current discussions.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.39.2-39.2
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• 2015

The World Space Observatory Ultraviolet (WSO-UV) is the space mission that will grant access to the UV range in the post Hubble epoch. WSO-UV is equipped with instrumentation for imaging and spectroscopy and it is fully devoted to UV astronomy. In this talk, we outline the WSO-UV mission model and present the current status of the project. Also, the NEO observing mission SODA (System of Observation of Day-time Asteroids) is also presented.

• Journal of the Korean Operations Research and Management Science Society
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• v.21 no.2
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• pp.203-213
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• 1996

A system is considered which is required to perform tasks that arrive randomly during a fixed mission duration. We develop queueing models to obtain the mission effectiveness and the blocking probabilities. Exact probabilities are computed by using the Finite Fourier Cosine Transform.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.304-311
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• 2022

Although the SEAD(suppression to enemy air defenses) mission is a strategically important task in modern warfare, the high risk of direct exposure to enemy air defense assets forces to use of unmanned aerial vehicles. this paper proposes a path planning algorithm for SEAD mission for an unmanned aerial vehicle and a method for calculating the mission effectiveness on the planned path. Based on the RRT-based path planning algorithm, a low-altitude ingress/egress flight path that can consider the enemy's short-range air defense threat was generated. The Dubins path-based Intercept path planning technique was used to generate a path that is the shortest path while avoiding the enemy's short-range anti-aircraft threat as much as possible. The ingress/intercept/egress paths were connected in order. In addition, mission effectiveness consisting of fuel consumption, the survival probability, the time required to perform the mission, and the target destruction probability was calculated based on the generated path. The proposed techniques were verified through a scenario.

• KIISE Transactions on Computing Practices
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• v.23 no.10
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• pp.579-587
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• 2017

Cyber Mission Impact Assessment is one of the essential tasks which many militaries and industrial major companies should perform to effectively achieve their mission. The unexpected damage to an organization's assets results in damage to the whole system's performance of the organizations. In order to minimize the damage, it is necessary to quantify the available capacity of the mission, which can be achieved only with the remaining assets, and to immediately prepare a new second best plan in a moment. We therefore need to estimate the exact cyber attack's impact to the mission when the unwanted damage occurs by modeling the relationship between the assets and the missions. In this paper, we propose a new model which deals with the dependencies between assets and missions for obtaining the exact impact of a cyber attack. The proposed model distinguishes task management from asset management for an efficient process, and it is implemented to be optimized using a vectorized operation for parallel processing and using a buffer to reduce the computation time.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.2
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• pp.159-166
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• 2020

In this paper, we propose a heterogenous mission allocation technique for multi-UAV system based on discrete event modeling. We model a series of heterogenous mission creation, mission allocation, UAV departure, mission completion, and UAV maintenance and repair process as a mathematical discrete event model. Based on the proposed model, we then optimize the number of UAVs required to operate in a given scenario. To validate the optimized number of UAVs, the simulations are executed repeatedly, and their results are analyzed. The proposed mission allocation technique can be used to efficiently utilize limited UAV resources, and allow the human operator to establish an optimal mission plan.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.56-63
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• 2016

We consider a satellite mission scheduling problem, which is a promising problem in recent satellite industry. This problem has various considerations such as customer importance, due date, limited capacity of energy and memory, distance of the location of each mission, etc. Also we consider the objective of each satellite such as general purpose satellite, strategic mission and commercial satellite. And this problem can be modelled as a general knapsack problem, which is famous NP-hard problem, if the objective is defined as to maximize the total mission score performed. To solve this kind of problem, heuristic algorithm such as taboo and genetic algorithm are applied and their performance are acceptable in some extent. To propose more efficient algorithm than previous research, we applied a particle swarm optimization algorithm, which is the most promising method in optimization problem recently in this research. Owing to limitation of current study in obtaining real information and several assumptions, we generated 200 satellite missions with required information for each mission. Based on generated information, we compared the results by our approach algorithm with those of CPLEX. This comparison shows that our proposed approach give us almost accurate results as just less than 3% error rate, and computation time is just a little to be applied to real problem. Also this algorithm has enough scalability by innate characteristic of PSO. We also applied it to mission scheduling problem of various class of satellite. The results are quite reasonable enough to conclude that our proposed algorithm may work in satellite mission scheduling problem.

• Journal of Astronomy and Space Sciences
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• v.17 no.2
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• pp.233-240
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• 2000

Five scientific instruments are planned on KAISTSAT-4 that is scheduled to be launched in 2002. A far ultra-violet imaging spectrograph and a set of space plasma instruments are currently being designed. The imaging spectrograph will make observations of astronomical objects and Earth's upper atmosphere. The plasma instrumentation is capable of fast measuring the thermal magnetosphere plasmas, cold ionospheric plasmas and the Earth's magnetic fields. Major system drivers and constraints on the payloads as well as the spacecraft are identified. A preliminary analysis of the K-4 mission has been undertaken with the system requirements that are derived from the system drivers. Detailed investigation shows that Sun-synchronous orbits with approximate altitudes of 800km are optimal to satisfy the identified requirements. Comparisons with other orbits of different inclinations are also shown. Four operation modes and a daily schedule of spacecraft maneuver are found from the Sun-synchronous orbital model. It is shown that the scientific objectives of K-4 can be achieved with moderate levels of design and operation risks.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.300-303
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• 2004

KOMPSAT-2 satellite mission operations and control system has been developed by ETRI. The system functional architecture, analysis and design, implementation, and tests are presented in this paper.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.49-57
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• 2020

The KC-100 has completed civil type certification with the Ministry of Land, Infrastructure, and Transport, and is currently under development as an unmanned aerial vehicle as part of the Ministry of Land, Infrastructure, and Transport. The Certification Technology of small Unmanned Airplane system (CTsUA system), which is an unmanned KC-100, is being developed to enable the installation of heavy-duty mission equipment and long-time flight missions. This study investigated the process and results of analyzing various parameters such as aircraft weight, airspeed, flight altitude, required horsepower, and fuel consumption at each stage to construct a mission profile based on the operational concept of the CTsUA system. To maintain a maximum take-off weight of 3,600 lbs (1,633 kg), the analysis determined that the weight of the application equipment for the unmanned system should be kept below 80 lbs (36 kg).