• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.3
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• pp.111-116
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• 2021

This study aims to identify the representative factors affecting the air trade between the two countries over the past 20 years, targeting China, Korea's largest trading partner for air transport. In the analysis, the two countries' GDP, GDP per capita, and tariff rates, as well as exchange rates, international oil prices, and FTAs were used as variables. For the analysis method, OLS multiple regression analysis was performed, and each was analyzed by dividing the export amount, import amount, and trade amount. As a result of the analysis, China's GDP and Korea's GDP per capita showed a positive (+) direction, an increase in the exchange rate resulted in an increase in the amount of trade, and an increase in the tariff rate resulted in a decrease in the amount of trade. Whether the FTA was concluded or not acted as a factor in increasing the amount of trade between the two countries.

• Journal of Astronomy and Space Sciences
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• v.35 no.4
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• pp.295-308
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• 2018

In this study, orbit determination (OD) simulation for the Korea Pathfinder Lunar Orbiter (KPLO) was accomplished for investigation of the observational arc-length effect using a sequential estimation algorithm. A lunar polar orbit located at 100 km altitude and $90^{\circ}$ inclination was mainly considered for the KPLO mission operation phase. For measurement simulation and OD for KPLO, the Analytical Graphics Inc. Systems Tool Kit 11 and Orbit Determination Tool Kit 6 software were utilized. Three deep-space ground stations, including two deep space network (DSN) antennas and the Korea Deep Space Antenna, were configured for the OD simulation. To investigate the arc-length effect on OD, 60-hr, 48-hr, 24-hr, and 12-hr tracking data were prepared. Position uncertainty by error covariance and orbit overlap precision were used for OD performance evaluation. Additionally, orbit prediction (OP) accuracy was also assessed by the position difference between the estimated and true orbits. Finally, we concluded that the 48-hr-based OD strategy is suitable for effective flight dynamics operation of KPLO. This work suggests a useful guideline for the OD strategy of KPLO mission planning and operation during the nominal lunar orbits phase.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.886-893
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• 2018

U.S. and the allies attacked chemical weapons sites in Syria in 2018, and verbal battles are carried out about the effectiveness of the air strike. Syria claimed 13 missiles were shot down, and Russia claimed 71 missiles were shot down while the U.S. released pictures of completely destroyed targets, only. It led controversy about the effectiveness of missile defense system. If there is a method to observe mission success rate of the air strike, it can not only improve combat awareness but also can be a good sales strategy in military industry. This paper describes effects and considerations of a Weapon Data Link(WDL) technology which can be used as a smoking gun of effectiveness. The paper describes WDL abilities such as In-Flight Track Update, Loiter, and Bomb Hit Indication etc., and presents examples of expected effectiveness of the WDL. In addition, this paper briefly summarizes operational consideration for better performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.227-229
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• 2016

Drone is demanding more than detaile hardware and software systems because Drone have characteristic flying. If Drone is a plane crash. they have risk of personal injury and property damage. now Drone control core system is preventing a plane crash and flight unsafe flying. The key is to help flying to convert for various external environment. This research prevent a plane crash that system planning to treat six-senser-figure doubly is IMU trouble or a trouble caused by a passing parameters and IMU install to help stability in flying.

• Journal of Satellite, Information and Communications
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• v.6 no.1
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• pp.37-44
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• 2011

COMS(Chollian) satellite which was launched on June 26, 2010 has three payloads for Ka-band communications, geostationary ocean color imaging and meteorological imaging. In order to make efficient use of the geostationary satellite, a concept of mission operations has been considered from the beginning of the satellite ground control system development. COMS satellite mission operations are classified by daily, weekly, monthly, and seasonal operations. Daily satellite operations include mission planning, command planning and transmission, telemetry processing and analysis, ranging and orbit determination, ephemeris and event prediction, and wheel off-loading set point parameter calculation. As a weekly operation, North-South station keeping maneuver and East-West station keeping maneuver should be performed on Tuesday and Thursday, respectively. Spacecraft oscillator updating parameter should be calculated and uploaded once a month. Eclipse operations should be performed during a vernal equinox and autumnal equinox season. In this paper, operational validations of the major functions in COMS SGCS are presented for the first three month of in-orbit test operations. All of the major functions have been successfully verified and the COMS SGCS will be used for the mission operations of the COMS satellite for 7 years of mission life time and even more.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.16-21
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• 2007

Various perturbations by the sun, the moon and the earth itself cause a continuous change in nominal position of a geostationary satellite. In order to maintain the satellite within a required window, north-south station keeping for controlling inclination and right ascension of ascending node, and east-west station keeping for controlling eccentricity and longitude are required. In this paper, station keeping maneuver simulation for Communication, Ocean and Meteorological Satellite (COMS) was performed using COMS Flight Dynamics Software(FDS) and the results were analyzed. COMS performs weekly based east-west/north-south station keeping to maintain satellite within ${\pm}0.05^{\circ}$ at the nominal longitude of $128.2^{\circ}E$. In addition, COMS performs wheel off-loading maneuver twice a day to eliminate attitude error caused by one-solar wing in the south panel of the satellite. In this paper, station keeping maneuver considering wheel off-loading maneuver was performed and the results showed that COMS can be maintained well within ${\pm}0.05^{\circ}$ window using COMS FDS.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.690-698
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• 2023

Information sharing and decision making between airport stakeholders became possible after the introduction of airport cooperative making system (A-CDM). This also resulted in optimizing aircraft handling time and increased the efficiency of aircraft operations. Technological advances have recently led to the development of urban air mobility (UAM) which is a small aircraft taking off and landing vertically. It is emerging as a new air transportation system in the future due to its advantage of saving time and solving congestion problem in the urban area. This study aims to suggest how vertiport cooperative decision making system (V-CDM) should be managed for efficient operation of UAM. By establishing procedure for decision making system based on Vertiport ecosystem of UAM. By establishing procedure for decision making system based on Vertiport ecosystem and UAM aircraft, unnecessary flight delays or cancellations can be minimized and efficiency of UAM operation will be improved as well.

• Journal of Aerospace System Engineering
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• v.13 no.6
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• pp.80-89
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• 2019

Prospecting future social environmental changes and improvement research on future technologies is required for prospecting promising technology, as it would be useful for institution·company to set up technical planning. This study aims at providing a methodology for retaining international technology competitiveness, marketable industry, and sustainable promising technology in a field of new growth engine industry such as national unmanned aerial vehicle industry. We draw a result by analysing with tools such as KrKwic, Excel, NetMiner, presenting methods of a Social Network Analysis, sub-group analysis, and cognitive map analysis based on patent data in a field of unmanned aerial vehicle industry. Therefore, this study explored the technology evolution of UAV and to prospect promising technology. As a result, some future promising technologies are prospected as what worths concentrated investment, such as 'system integration tech', 'assessment/airworthiness certification tech', 'avionics', 'pilot control tech', 'identification of friend or foe', 'flight control tech', 'supportive equipment'.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.3
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• pp.432-441
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• 2016

Solar energy is the ideal power choice for long-endurance stratospheric airships. The output performance of solar array on stratospheric airship is affected by several major factors: flying latitude, flight date, airship's attitude and the temperature of solar cell, but the research on the effect of these factors on output performance is rare. This paper establishes a new simplified analytical model with thermal effects to analyze the output performance of the solar array. This model consisting of the geometric model of stratospheric airship, solar radiation model and incident solar radiation model is developed using MATLAB computer program. Based on this model, the effects of the major factors on the output performance of the solar array are investigated expediently and easily. In the course of the research, the output power of solar array is calculated for five airship's latitudes of $0^{\circ}$, $15^{\circ}$, $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$, four special dates and different attitudes of five pitch angles and four yaw angles. The effect of these factors on output performance is discussed in detail. The results are helpful for solving the energy problem of the long endurance airship and planning the airline.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.151-158
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• 1992

Topographic mapping from economic SPOT stereo imagery than aerial photographs has become possible. Many of authors have studied the possibility of base map revisions and the accuracy of results. They have concluded that the SPOT image is suitable for 1/50,000 to 1/100,000 topographic map. For topographic map, orthophoto and DTM generation from SPOT imagery, accurate exterior orientation parameters are needed. But since the geometric characteristic of SPOT image is dynamic linear array imagery, the conventional bundle adjustment for photogrammetry can not be directly applied. Reliability is the ability to detect gross error, which is called the internal reliability, and the effect of non-detectable gross error on the results of exterior orientation, which is called the external reliability. This paper shows how the reliability of SPOT imagery depends on the different coordinate systems, presentations of coordinate for flight direction, orders of exterior orientation parameters and distribution of control points, and thus analyses the theoretical reliability of the exterior orientation, which can provide a basis for the planning of SPOT projects.