다중 냉각유로가 적용된 수랭식 군사용 대면적 안테나의 열성능 예측 기술

이예륜,장성욱,최필경,곽노진,박준정 한국군사과학기술학회 2024 한국군사과학기술학회지 Vol.27 No.1

Large planar military antenna boasts a range of electrical components, including TRA(Transmit-Receive Assembly), signal processors, etc. which engage in computations and calculations. These processes generate a significant amount of heat, leading to unforeseen consequences for the equipment. To mitigate these adverse effects, it's imperative to implement a cooling system that can effectively reduce heat-related issues. Given the antenna's intricate nature and the multitude of components it houses, a two-step estimation process is necessary. The first step involves a comprehensive model calculation to determine the total flow characteristics, while the second step entails a thermal analysis of individual TRA set. In this study, we depicted an antenna set using simplified 3D models of its components, considering their material and thermal properties. The sequential analysis process facilitated the calculation of branched flow rates, providing insights into the individual TRA. This approach also allowed us to design a cooling system for the TRA set, assessing its thermal stability in high-temperature environments. To ensure the optimal performance of TRA, breaking down the analysis into stages based on the cooling system's structure can assist operators in predicting numerical results more effectively .

한국적 무기체계의 워게임 모델 교정에 관한 연구

정건호,염봉진,Jung, Kun-Ho,Yum, Bong-Jin 한국군사과학기술학회 2009 한국군사과학기술학회지 Vol.12 No.2

Some of the wargame simulators currently used in the Korean Army were developed by other countries, and do not adequately reflect the Korean Peninsula terrain and weapon systems. This implies that these war game simulators need to be calibrated with respect to the input parameters for properly assessing the effectiveness of the Korean weapon systems. In this paper, AWAM, a wargame simulator, is calibrated in terms of the time-based fighting power(FP). The FP data obtained from the Korea Combat Training Center(KCTC) are used as a reference, and the differences between the AWAM and KCTC FP data are calculated at certain points in time. Then, the Taguchi robust design method is adopted using the probabilities of hitting for the K-2 rifle as controllable input parameters. Two performance characteristics are used. One is the difference between the AWAM and KCTC FP data and the other is the score derived by grouping the difference data. For each case, optimal settings of the probabilities of hitting are determined such that the mean of each characteristic is close to 0 with its dispersion being as small as possible.

CASE 도구를 활용한 기능범주 분석 기반 이지스급 함정의 한국적 탄도미사일방어 JIC 도출

임종수,권용수,이경행,Lim, Chong-Su,Kwon, Yong-Soo,Lee, Kyoung-Haing 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.3

This work describes a derivation process of JIC(Joint Integrating Concept) based JFC(Joint Functional Concept) analysis of an Aegis BMD(Ballistic Missile Defense). JIC is developed through JOC(Joint Operating Concept) and JFC based on capstone strategy and concept. Aegis BMD is a sea-based ballistic missile defense to detect ballistic missile threat, increase engagement battlespace and enable multiple engagement based on Aegis ships. Aegis BMD is a good case of JIC due to performing an Joint operations based on System of Systems under highly complicated NCW environment. This work analyses JFC using QFD(Quality Function Deployment) and UJTL(Universal Joint Task List). From this analysis the JIC of Aegis Korean BMD is derived using a CASE tool.

한국형기동헬기 임무컴퓨터 비행필수기능 설계

유연운,김태열,장원홍,김성우,임종봉,Yu, Yeon-Woon,Kim, Tae-Yeol,Jang, Won-Hong,Kim, Sung-Woo,Lim, Jong-Bong 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.2

Avionics system tends to be designed to have the integrated architecture, and it is getting difficult and complex to verify the flight-critical function because of sophisticated structure. In Korean Utility Helicopter, mission computer acts as the MUX Bus Controller to handle the data from both communication, identification, mission/display and survivability equipment inside Mission Equipment Package and aircraft subsystems such as fuel system and electrical system while it is interfacing with Automatic Flight Control System and Full-Authority Digital Engine Control via ARINC-429 bus. The Flight Displays which is classified as flight-critical function in aircraft is implemented on Primary Flight Display after mission computer processes data from AFCS in order to generate graphics. This paper defines the flight-critical function implemented in mission computer for KUH, and presents the static and dynamic test procedures which is performed on System Integration Laboratory along with Playback Recorder prior to flight test.

한국형 공중 시뮬레이터 항공기 연구

고준수,안종민,박성수,Ko, Joon-Soo,Ahn, Jong-Min,Park, Sung-Su 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.6

This paper presented here contains development of variable stability system(VSS) control laws for the KIFS (Korean In-Flight Simulator) aircraft to simulate the dynamics of F-16 aircraft. Development of VSS Control law for pitch rate, roll rate, yaw rate simulation for three specified flight conditions using Model Following Technique with rate feedback autopilot for stability provision. The direct lift force controller was also added to the developed VSS control law to simulate the pitch rate and normal g-load simultaneously. The simulation results show high accuracy of F-16 aircraft's pitch, roll, yaw rate and g-load simulation.

한국형 미래전투체계 효과도 분석을 위한 회전익 무장체계 시뮬레이션

홍정완,박상철,권용진,Hong, Jungwan,Park, Sang C.,Kwon, Yongjin 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.4

This research is to develop a simulation framework to gauge the mission effectiveness of the rotorcraft system that will be a part of Korean future combat system. The rotorcraft system comprises of many subsystems that are very time-consuming and tedious to model. Each subsystem and its characteristics have been modeled using component-based modeling techniques, which enhances its reusability. The entire system is then constructed from the individually modeled component, which significantly reduces the modelling time. The mission effectiveness of the rotorcraft system is simulated using the developed models, and the output indicates that the methodology proposed in this study is useful, which will be suitable for the modeling and simulation of Korean future combat system.

M-추정을 사용한 국방과학기술 수준조사 기술성장모형의 이상치 제거

김장헌,Kim, Jangheon 한국군사과학기술학회 2020 한국군사과학기술학회지 Vol.23 No.1

Technology growth curve methodology is commonly used in technology forecasting. A technology growth curve represents the paths of product performance in relation to time or investment in R&D. It is a useful tool to compare the technological performances between Korea and advanced nations and to describe the inflection points, the limit of improvement of a technology and their technology innovation strategies, etc. However, the curve fitting to a set of survey data often leads to model mis-specification, biased parameter estimation and incorrect result since data through survey with experts frequently contain outlier in process of curve fitting due to the subjective response characteristics. This paper propose a method to eliminate of outlier from a technology growth curve using M-estimator. The experimental results prove the overall improvement in technology growth curves by several pilot tests using real-data in Defense Science and Technology Survey reports.

한국어 립리딩: 데이터 구축 및 문장수준 립리딩

조선영,윤수성 한국군사과학기술학회 2024 한국군사과학기술학회지 Vol.27 No.2

Lip-reading is the task of inferring the speaker’s utterance from silent video based on learning of lipmovements. It is very challenging due to the inherent ambiguities present in the lip movement such as differentcharacters that produce the same lip appearances. Recent advances in deep learning models such as Transformerand Temporal Convolutional Network have led to improve the performance of lip-reading. However, most previousworks deal with English lip-reading which has limitations in directly applying to Korean lip-reading, and moreover,there is no a large scale Korean lip-reading dataset. In this paper, we introduce the first large-scale Koreanlip-reading dataset with more than 120 k utterances collected from TV broadcasts containing news, documentary anddrama. We also present a preprocessing method which uniformly extracts a facial region of interest and propose atransformer-based model based on grapheme unit for sentence-level Korean lip-reading. We demonstrate that ourdataset and model are appropriate for Korean lip-reading through statistics of the dataset and experimental results.

한국 국방 연구개발 프로젝트 일정 관리 및 예측을 위한 Earned Schedule 기법의 적용 효과와 한계 분석

조정호,임재성,Cho, Jungho,Lim, Jaesung 한국군사과학기술학회 2018 한국군사과학기술학회지 Vol.21 No.3

Earned Value Management(EVM) has been used to manage and forecast defense project schedule and cost over the last two decades in the world. However to support the lacking ability of schedule analysis in traditional EVM, earned schedule(ES) has been introduced as a tool to more accurately estimate schedule performance. This paper compares which method EVM or ES, provides more accurate schedule predictors in 32 Korean defense research and development projects. As a result of comparison, the ES method can predict the future schedule more reliably than the EVM method. We also analyze early warning function of schedule performance index considering project duration extension point. Through the analysis results, we confirm that both the EVM and the ES method lack the ability of the early warning in terms of the current schedule management criterion.

한국형 저비용 저고도 공중보급 체계용 낙하산 전개 특성 풍동시험

김승필,정인식,권기범,최윤석,정형석,Kim, Seung Pil,Jung, Insik,Kwon, Kybeom,Choi, Younseok,Chung, Hyoungseog 한국군사과학기술학회 2017 한국군사과학기술학회지 Vol.20 No.3

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.