• 한국군사과학기술학회지
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• 제10권4호
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• pp.20-29
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• 2007

The engagement control software embedded in the weapon control computer of the fire control center for air defense missile system is large-scale real-time software. The use of typical software development methodologies is not appropriate to develop such large-scale embedded software in terms of reusability, reliability, and productivity for the reason that it is significantly complicated, and highly dependent on hardware platforms and developers. In this paper, a model-based software architecture using components based on UML 2.0 for the engagement control software is presented in order to solve these problems. This software architecture is verified using the black-box test, the scenario-based test, and the Ethernet packet monitoring test methods. The results demonstrate that the developed software architecture can be employed to enhance reusability, maintainability, and productivity of large-scale embedded software.

• 인터넷정보학회논문지
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• 제4권6호
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• pp.1-11
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• 2003

이 논문은 유스 케이스 기반 실시간 시스템을 위한 디자인 지향 테스트를 소개한다. 우리는 디자인 스키마를 기능적 컴포넌트의 계층적 디자인 컴포넌트 아키텍처(즉 디자인 컴포넌트)로 분할 하는 실시간 소프트웨어 개발을 위한 확장 유스 케이스에 초점을 둔다. 실행 순차의 다양한 유스 케이스의 액션 단위를 기술하는 관련된 시나리오를 포함하는, 즉 실시간 시스뎀 설계의 동적 특성을 반영하는, 유스 케이스 액션 메트릭스를 제안한다. 실시간 시스템을 제안한 디자인 지향 테스트에 적용 시도를 통해 생산성 향상을 위한 시나리오 순서화를 생성하고 기존의 테스트 케이스 재사용을 진작시킨다.

• International Journal of Aeronautical and Space Sciences
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• 제18권4호
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• pp.740-756
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• 2017

This paper proposes a feedback-linearization-based control algorithm for multirotor unmanned aerial vehicles (UAVs). The feedback linearization scheme is highly efficient for considering nonlinearity between the rotational and translational motion of multirotor UAVs. We also propose a dynamic equation that reflects the aerodynamic effects of the vehicles; the equation's parameters can be determined through curve fitting using actual flight data. We derive the feedback linearization controller from the proposed dynamic equation, and propose a Luenberger observer to attenuate measurement noises. The proposed algorithm is implemented using our in-house flight control computer, and we describe its implementation in detail. To investigate the performance of the proposed algorithm, we carry out two flight scenarios: the first scenario, an autonomous landing on a moving platform, is a test of maneuverability; the second, picking up and replacing an object, test the algorithm's accuracy. In these scenarios, the proposed algorithm precisely controls multirotor UAVs, and we confirm that it can be successfully applied to real flight environments.

• Journal of Astronomy and Space Sciences
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• 제31권4호
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• pp.295-301
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• 2014

Whistler mode chorus wave is considered to play a critical role in accelerating and precipitating the electrons in the outer radiation belt. In this paper we test a conventional scenario of triggering chorus using THEMIS satellite observations of waves and particles. Specifically, we test if the chorus onset is consistent with development of anisotropy in the electron phase space density (PSD). After analyzing electron PSD for 73 chorus events, we find that, for ~80 % of them, their onsets are indeed associated with development of the positive anisotropy in PSD where the pitch angle distribution of electron velocity peaks at 90 degrees. This PSD anisotropy is prominent mainly at the electron energy range of ${\leq}$ ~20 keV. Interestingly, we further find that there is sometimes a time delay among energies in the increases of the anisotropy: A development of the positive anisotropy occurs earlier by several minutes for lower energy than for an adjacent higher energy.

• International Journal of Contents
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• 제4권2호
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• pp.19-23
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• 2008

This paper presents a novel method to construct a personalized e-Learning system based on dynamic estimations of item parameters and learners' abilities, where the learning content objects are of the same intrinsic quality or homogeneously distributed and the estimations are carried out using IRT(Item Response Theory). The system dynamically connects the test and the corresponding learning procedures. Test results are directly applied to estimate examinee's ability and are used to modify the item parameters and the difficulties of learning content objects during the learning procedure is being operated. We define the learning unit 'Node' as an amount of learning objects operated so that new parameters can be re-estimated. There are various content objects in a Node and the parameters estimated at the end of current Node are directly applied to the next Node. We offer the most appropriate learning Node for a person's ability throughout the estimation processes of IRT. As a result, this scheme improves learning efficiency in web-base e-Learning environments offering the most appropriate learning objects and items to the individual students according to their estimated abilities. This scheme can be applied to any e-Learning subject having homogeneous learning objects and unidimensional test items. In order to construct the system, we present an operation scenario using the proposed system architecture with the essential databases and agents.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제5권4호
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• pp.165-170
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• 2016

안드로이드 어플리케이션은 인텐트를 이용하여 다른 어플리케이션의 컴포넌트를 호출하여 실행시킬 수 있다. 하지만 컴포넌트들 사이의 상호작용이 정상적으로 처리되지 않으면 잘못된 컴포넌트가 실행되거나 전화 수신과 같은 시스템 브로드캐스트를 처리하지 못하는 문제점이 발생할 수 있다. 본 논문에서는 이와 같은 상호작용 문제점을 검사하기 위해 서로 연동하여 동작하는 어플리케이션들로부터 컴포넌트 기반의 다이어그램들을 생성하고 이를 하나의 병합된 다이어그램으로 변환하여 테스트 시나리오를 생성하는 방법을 제안한다. 제안된 방식은 기존의 테스팅 기법에서 고려하지 못한 어플리케이션간의 상호작용 검사를 효율적으로 수행할 수 있다.

• 항공우주기술
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• 제2권1호
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• pp.117-123
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• 2003

본 논문에서는 3단형 과학로켓 KSR-III의 발사에 사용된 지상 추진제 공급설비를 소개하고 설비의 구성, 개발현황에 대하여 기술하고자 한다. 발사장 내의 추진제 공급설비는 KSR-III의 비행시험을 위해 발사 시나리오에 따라 발사체에 추진제 및 가압제를 각 요구조건에 부합하게 공급하는 설비이다. 구현된 공급설비는 크게 추진제 및 가압제 저장/공급 설비와 제어계측 설비로 구성되며 각종 입증시험과 연계시험을 통하여 그 성능 검증을 마친 후 KSR-III 비행시험에 성공적으로 사용되었다.

• Journal of Positioning, Navigation, and Timing
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• 제4권1호
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• pp.9-16
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• 2015

The applications of Global Navigation Satellite System (GNSS) receivers are becoming wider in various commercial and military systems including even small weapon systems such as artillery shells. The precision-guided munitions such as Small Diameter Bomb (SDB) of United States can be used for pinpoint strike by acquiring and tracking GNSS signals in high mobility situation. In this paper, a small GNSS receiver with embedded interference suppression capability working under high dynamic stress is developed which is applicable to the various weapon systems and can be used in other several harsh environments. It applies a kind of matched filter and multiple correlator schemes for fast signal acquisition and tracking of even weak signals and frequency domain signal processing method to eliminate the narrowband interference. To evaluate the performance of the developed GNSS receiver, the test scenario of high mobility and interference environment with the GNSS simulator and signal generator is devised. Then, the signal acquisition time, navigation accuracy, sensitivity, and interference suppression performances under high dynamic operation are evaluated. And the comparison test with the commercial GNSS receiver which has high sensitivity is made under the same test condition.

• 한국군사과학기술학회지
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• 제14권2호
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• pp.181-188
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• 2011

A simulation technique, which simulate dynamic motion and communication environments of ship in the lab, is needed in order to reduce the testing cost when we evaluate the transfer alignment performance of shipboard INS. Hardware-In-the-Loop Simulation(HILS) can be used as an effective test method for those system because it can provide flexible and realistic simulation environments, various test scenario, and repeated test environment in the lab without additional cost and person. This paper presents the methods for implementing the real time HILS environment for testing transfer alignment performance of shipboard INS. It includes real time executive for controlling realtime simulation and calculating the ship motion, communication method for interfacing between the systems, and coordinate transformation method for converting real ship coordinate attitude data to lab coordinate attitude data.

• Nuclear Engineering and Technology
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• 제48권2호
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• pp.505-517
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• 2016

The structural integrity of a dual-purpose metal cask currently under development by the Korea Radioactive Waste Agency (KORAD) was evaluated, through numerical simulations and a model test, under high-speed missile impact reflecting targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from literature. In the impact scenario, a missile flying horizontally hits the top side of the cask, which is freestanding on a concrete pad, with a velocity of 150 m/s. A simplified missile simulating a commercial aircraft engine was designed from an impact loade-time function available in literature. In the analyses, the dynamic behavior of the metal cask and the integrity of the containment boundary were assessed. The simulation results were compared with the test results for a 1:3 scale model. Although the dynamic behavior of the cask in the model test did not match exactly with the prediction from the numerical simulation, other structural responses, such as the acceleration and strain history during the impact, showed very good agreement. Moreover, the containment function of the cask survived the missile impact as expected from the numerical simulation. Thus, the procedure and methodology adopted in the structural numerical analyses were successfully validated.