• 대기
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• 제34권3호
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• pp.273-281
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• 2024

Analyzing the information about climate change on Korean Peninsula is essential for the national defense. In this study, we used HadGEM3-RA model output (a member of CORDEX-EA) and analyzed the 3 operational weather factors (VMC, runway temperature, WBGT), which affect the aircraft field. The number of future limited days was quantitatively calculated based on the model outputs applying SSP1-2.6 and SSP5-8.5 and the operational limits of the previous three factors, and the spatial distribution, time series, and correlation of each result were analyzed. In conclusion, it was analyzed that the number of limited days by VMC would decrease, resulting from the rise in temperature and the drop in relative humidity. This means the operational environment in VMC will improve. On the other hand, the number of limited days by the runway temperature and WBGT would increase, resulting from the rise in temperature. This means the operational environment in runway temperature and WBGT will worsen.

• 한국군사과학기술학회지
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• 제26권5호
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• pp.431-438
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• 2023

The information about battlefield environment changes and operational impacts on Korean Peninsula due to climate change is essential for national defense. In this study, the future impact of four ground operations was analyzed by using the national climate change standard scenario based on the IPCC 6^th report. As a result, it was analyzed that the number of operational-limited days for ambush and airlift operations would decrease, making the operational environment favorable. However, the operational environment unfavorable as the number of operational-limited days for crossing and reconnaissance operations increase, but the number is not large so much.

• 한국군사과학기술학회지
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• 제20권3호
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• pp.345-351
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• 2017

A wind tunnel test for the scaled parachute models was performed to verify aerodynamic characteristics for practical usage of Korean low cost low altitude aerial delivery system. The cruciform shaped cargo parachute models for heavy and light weight were ejected into wind tunnel test section; and the drag forces acting on the models in steady condition were measured in accordance with velocity. Also, the maximum opening forces during inflation were obtained and captured by a high speed camera to analyze the inflation characteristics and evaluate the design of the low cost aerial delivery system. The results showed a reliable stability and met the design requirement of delivery operation system for R.O.K Air Force.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2023년도 추계학술발표대회
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• pp.1051-1052
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• 2023

조류충돌(Bird Strike)은 경제적 손실, 인명적 피해를 야기하여 공군의 항공작전을 제한하는 위협요소이다. 현 공군에서는 조수퇴치조(Bird Alert Team)의 경보 발령에 의존하거나 조류의 행동을 연구하는 등 인적 역량에 의존하는 시스템을 채택하고 있다. 본 연구는 CNN을 이용하여 활주로의 유해조류를 인식 및 분류하는 자동화 시스템에 대한 제안이다. 웹캠을 활용한 실시간 유해조류를 인식하는 연구를 통해 향후 운항관제대와의 연계, 지향성 조류퇴치 장비와의 연동 방안을 제시하여 공군의 조수퇴치조(Bird Alert Team)에 대한 자동화를 실현하고 공군에서 추진중인 스마트 비행단에 이바지하고자 한다.

• Corrosion Science and Technology
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• 제20권2호
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• pp.94-104
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• 2021

Atmospheric corrosion severity associated with aircraft parking environment was studied using metallic specimens, and temperature and humidity sensors installed at each aircraft operating base. Data were analyzed after a year of exposure. Silver was used to measure chloride deposition by integrating X-ray photoelectron spectroscopy depth profiles. Carbon steel was utilized to determine the corrosion rate by measuring the weight loss. The time of wetness was determined using temperature and humidity sensor data. Analysis of variance followed by Tukey's "honestly significant difference" test indicated that atmospheric environment inside the shelter varied significantly from that of unsheltered parking environment. The corrosion rate of unsheltered area also varies with the roof. Hierarchical clustering analysis of the measured data was used to classify air bases into groups with similar atmospheric corrosion. Bases where aircraft park at a shelter can be grouped together regardless of geographical location. Unsheltered bases located inland can also be grouped together with sheltered bases as long as the aircraft are parked under the roof. Environmental severity index was estimated using collected data and validated using the measured corrosion rate.

• International Journal of Aeronautical and Space Sciences
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• 제11권4호
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• pp.345-350
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• 2010

The repetitive vibrating action of an aerodynamic load causes an external fuel tank's horizontal fin to experience a shorter life cycle than its originally predicted one. Store separation analysis is needed to redesign the fin of an external fuel tank. In this research, free-drop tests were conducted using 15% scaled models in a subsonic wind tunnel in order to analyze the store separation characteristics of an external fuel tank. The store separation trajectory based on grid tests was also obtained to verify the results of the free-drop tests. The results acquired from the free-drop tests correlated well with the grid tests in regards to the trajectories and behavior of the stores separated from the aircraft. This agreement was especially noted in the early stages of the store separation.

• Journal of Preventive Medicine and Public Health
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• 제47권4호
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• pp.230-235
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• 2014

Objectives: The aim of this study was to investigate whether the health status of Republic of Korea Air Force (ROKAF) soldiers changed after one year of military service. Methods: We selected 483 ROKAF soldiers from the 11 749 recruits who participated in the 2011 physical examination. The selected soldiers underwent another physical examination in 2012 for advancement to senior airman. Data from 2011 and 2012 were merged. To collect data on lifestyle, a questionnaire was sent to all included subjects via the military intranet e-mail service. Results: The percentage of recruits with an abnormal alanine transaminase level (normal range <40 IU/L) decreased from recruitment (13.7%) to the following year (2.7%). Moreover, the percentage of obese soldiers (body mass index ${\geq}25kg/m^2$) decreased from recruitment (20.5%) to the following year (10.4%). There was a significant change in mean duration of exercise carried out each day before ($0.8{\pm}1.3$ hours) and after ($1.0{\pm}0.7$ hours) joining the ROKAF service. Conclusions: These ROKAF soldiers were generally in good health before and after joining the armed service. After one year of military service, the health status of most soldiers improved, especially with respect to body mass index and alanine transaminase level.

• 공학교육연구
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• 제24권5호
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• pp.38-45
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• 2021

The CanSat was designed as an educational satellite simulation program that implements the overall system of the satellite such as the command processing unit, the communication unit, and the power unit in a structure of the size of a can. In particular, the training effect is very excellent because the trainee can learn a process similar to the actual satellite development process by designing, manufacturing, testing, and launching. Republic of Korea Air Force Academy has been using the CanSat production kit used by the domestic can satellite contest experience department for education, but since it was produced based on PCB, it was impossible to show creativity and operation was restricted even with small mistakes. In this paper, we analyze the existing CanSat kit and propose a new educational CanSat kit that can be used in creative engineering design and practice subjects that will be reorganized into a regular course from 2021, and a lesson plan. In conclusion, by using the proposed CanSat kit for lectures, it is possible to achieve educational purposes and effects, improve lecture satisfaction, and provide stable instruction.

• 한국항공우주학회지
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• 제50권8호
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• pp.573-581
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• 2022

본 논문은 단풍나무 씨앗형 자동회전 과학 탑재체 2개를 사출하고 기상정보를 수집하는 임무를 하는 캔위성을 개발하는 내용을 다루고 있다. 캔위성은 2개의 자동회전형 과학 탑재체와 이를 실을 수 있는 캔위성 본체로 구성된다. 캔위성 본체는 과학 탑재체를 사출하기 위한 장치들과 지상국과의 통신을 위한 장치들을 탑재하고, 각기 다른 지정 고도에서 과학 탑재체를 하나씩 사출한다. 과학 탑재체는 큰 날개와 탑재 공간으로 구성되며, 큰 날개는 회전하면서 양력을 발생시켜 낙하 속도를 늦춘다. 구체적으로, 사출된 이후 20m/s 이하의 속도로 하강하며 회전율, 기압과 온도를 측정하고 초당 1회의 속도로 측정값을 캔위성본체로 송신한다. 통신 시스템은 마스터-슬레이브 구조로 과학 탑재체는 모든 데이터를 마스터인 캔위성본체로 송신하고, 캔위성 본체는 수신받은 데이터와 자체 데이터를 종합하여 지상국으로 전송한다. 자체 개발한 지상국 소프트웨어를 이용해 수신하는 모든 데이터를 실시간으로 확인할 수 있다. 시뮬레이션 환경에서 모의실험을 수행했고, 임무 요구조건을 만족하는 캔위성의 성능을 확인할 수 있었다.

• 대기
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• 제21권2호
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• pp.197-208
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• 2011

The objective of this study is to describe the short-range forecast system of the Korea Air Force (KAF) and to verificate its performace in 2009 summer. The KAF weather prediction model system, based on the Weather Research and Forecasting (WRF) model (i.e., the KAF-WRF), is configured with a parent domain overs East Asia and two nested domains with the finest horizontal grid size of 2 km. Each domain covers the Korean peninsula and South Korea, respectively. The model is integrated for 84 hour 4 times a day with the initial and boundary conditions from National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) data. A quantitative verification system is constructed for the East Asia and Korean peninsula domains. Verification variables for the East Asia domain are 500 hPa temperature, wind and geopotential height fields, and the skill score is calculated using the difference between the analysis data from the NCEP GFS model and the forecast data of the KAF-WRF model results. Accuracy of precipitation for the Korean penisula domain is examined using the contingency table that is made of the KAF-WRF model results and the KMA (Korea Meteorological Administraion) AWS (Automatic Weather Station) data. Using the verification system, the operational model and parallel model with updated version of the WRF model and improved physics process are quantitatively evaluated for the 2009 summer. Over the East Aisa region, the parallel experimental model shows the better performance than the operation model. Errors of the experimental model in 500 hPa geopotential height near the Tibetan plateau are smaller than errors in the operational model. Over the Korean peninsula, verification of precipitation prediction skills shows that the performance of the operational model is better than that of the experimental one in simulating light precipitation. However, performance of experimental one is generally better than that of operational one, in prediction.