• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.691-698
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• 2020

In this study, the effects of hydrodynamic interceptors on a high-speed vessel were investigated to identify the operating principle based on experiments. Model tests were performed using a high-speed towing carriage. The resistance, trim and rise of Center of Gravity (CG) of the high-speed vessel were measured for various ship speeds and interceptor heights. As the interceptor height increased, the trim and rise of CG were reduced. In order to quantitatively analyze these phenomena, the pressure at the stern bottom was measured using tactile sensors. The reliability of the measured results from the tactile sensors was verified through repeat tests. The pressure on the stern bottom increased in proportion to the interceptor height, as the interceptor partially blocked the flow there. Then, the trim was reduced. However, as the ship speed increases, the pressure at the location close to the interceptor decreases when the interceptor height is small, leading to increased trim. Therefore, the interceptor height for running attitude control should be carefully determined considering multiple factors in the operating condition of the high-speed planing hull.

• 한국시뮬레이션학회논문지
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• 제29권2호
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• pp.49-61
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• 2020

탄도미사일 위협에 대응하기 위해 제한된 수량의 요격미사일을 효율적으로 운용하는 것은 중요하다. 기존 요격미사일 운용방법은 방호목표에 적용하는 교전효과수준에 따라 요격미사일 수를 결정한다. 이는 요격확률에 비해 과도한 요격미사일 소모 또는 요격확률 감소를 초래할 수 있다. 따라서 탄도미사일 수와 요격확률 및 비용을 고려하여 요격미사일 운용방법을 결정해야한다. 본 연구는 요격미사일 운용방법을 개선하기 위한 수리모형을 제안한다. 또한, 요격확률과 비용의 절충을 위해 효율성 지표를 제시하였다. 시뮬레이션 결과 수리모형 기반 요격미사일 운용방법이 기존 요격미사일 운용방법에 비해 우수한 결과를 달성할 수 있었다.

• 한국습지학회지
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• 제20권3호
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• pp.219-226
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• 2018

차집관로는 국유지가 많은 하천변에 매설되어 있어 파손이나 침입수/유입수(불명수, I/I) 의 유입으로 공공하수처리시설의 운영효율이 떨어지며, 하수관로 정비사업의 효율도 저하되는 것으로 나타났다. 본 연구는 하수관로 정비사업 효과의 감소원인에 가장 많은 영향을 미치는 차집관로를 대상으로 감소원인에 대한 분석을 하였다. 즉, 대상지역 3개소를 선정하여 차집관로의 현황조사(관로연장, 관경, 관종, 매설년도, 매설위치 등), 차집관로에 대한 차수(Pump 작업) 및 준설작업을 병행한 관로내부(CCTV)조사, 맨홀내부(육안)조사, 유량 및 수질조사 결과를 이용한 오염부하량 산정 등을 수행하였다. 합류지역은 동시 다측점 유량조사와 차집관로 유량 및 수질(BOD)조사, 오염부하량 비교 등을 수행하였으며, 차집관로 부실화에 따른 침입수/유입수 발생 현황 등 실태조사를 실시하였다. 연구결과, 하수관로정비 사업의 효과를 감소시키는 주요 원인은 차집관로의 노후화 및 미정비로 인해 공공 하수처리시설로 저농도 하수 및 불명수 유입되기 때문인 것으로 분석되었다.

• International Journal of Aeronautical and Space Sciences
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• 제16권2호
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• pp.278-294
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• 2015

Considering the guidance and control problem of the near space interceptor (NSI) during the terminal course, this paper proposes a three-channel independent integrated guidance and control (IGC) scheme based on the backstepping sliding mode and finite time disturbance observer (FTDO). Initially, the three-channel independent IGC model is constructed based on the interceptor-target relative motion and nonlinear dynamic model of the interceptor, in which the channel coupling term and external disturbance are regarded as the total disturbances of the corresponding channel. Then, the FTDO is introduced to estimate the target acceleration and control system loop disturbances, and the feed-forward compensation term based on the estimated values is employed to effectively remove the effect of disturbances in finite time. Subsequently, the IGC algorithm based on the backstepping sliding mode is also given to obtain the virtual control moment. Furthermore, a robust least-squares weighted control allocation (RLSWCA) algorithm is employed to distribute the previous virtual control moment among the corresponding aerodynamic fins and reaction jets, which also takes into account the uncertainty in the control effectiveness matrix. Finally, simulation results show that the proposed IGC method can obtain the small miss distance and smooth interceptor trajectories.

• 한국ITS학회 논문지
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• 제7권4호
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• pp.97-106
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• 2008

본 시스템은 ITS 정보 감사를 지원하기 위한 내부 통제 시스템의 일부이다. 이 시스템은 중요 도로정보 시스템 서버에 접근하는 패킷을 가로챈 후 SQL 쿼리를 분석하여, 접속한 사용자 정보와 데이터 베이스에 접근하려는 DB 정보, 데이터에 대한 조회, 변경, 삭제 정보를 로그로 기록한다. 이 로그 정보는 사용자의 내부 통제 및 데이터베이스 접근 증거로 사용될 수 있다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.256-273
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• 2019

Nowadays interceptors have been widely used in a vast range of high-speed crafts. In this study, the results of interceptor adeptness experiments made in Istanbul Technical University's Towing Tank are unveiled. The model was tested through three transverse locations of interceptors with six different deployment depths. For three locations, the interceptor was positioned transverse on the aft; close to chine, in the middle and close to the keel. The fourth interceptor was a full length of 13.00% LWL. The results show a significant drag reduction in benefits of 1.50%-11.30% for Fn 0.58-1.19 and the trim reduction was observed in between 1.60 and $4.70^{\circ}$. Besides, one of the most significant conclusions indicates that the effect of the interceptor decreases from keel to chine for the same blade deployment heights so the blades should be controlled separately at least in three parts from keel to chine area, if operable.

• 해양환경안전학회지
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• 제25권5호
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• pp.601-608
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• 2019

본 연구에서는 선수 돌출의 반전형 선수 형상을 가진 고속 쌍동선의 선체부착 부가물에 의한 주행성능 영향에 대하여 수치해석과 회류수조 모형시험을 통하여 비교분석하였다. 반전형 선수 형상은 재래식 선수 형상보다 선수 발산파 파정의 생성위치를 선미방향으로 이동시켜 개선된 조파형상을 보이며, 저항 및 안정된 항주자세에 효과적임을 보였다(Kim et al., 2019). 본 연구에서의 반전형 선수 내측에 부착된 핀과 선미단 인터셉터(Interceptor)에 의한 파형과 항주자세 변화 등 주행성능에 대한 모형시험 결과에서는, 1) 반전형 선수의 Trim 특성 2) Fin에 의한 내측 파의 중첩 개선 3) Fin과 Interceptor에 의한 자세제어는 두 선체 연결갑판(Wetdeck) 충격을 줄이는데 효과적인 것으로 판단된다.

• International Journal of Aeronautical and Space Sciences
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• 제15권2호
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• pp.153-162
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• 2014

A novel robust $H_{\infty}$ switching tracking control design method with disturbance observer is proposed for the near space interceptor (NSI) with aerodynamic fins and reaction jets. Initially, the flight envelop of the NSI is divided into small subregions, and a slow-fast loop polytopic linear parameter varying (LPV) model is proposed, to approximate the nonlinear dynamic of the NSI, based on the Jacobian linearization and Tensor-Product (T-P) model transformation approach. A disturbance observer is then constructed, to estimate the modeled disturbance. Subsequently, based on the descriptor system method, a robust switching controller is developed, to ensure that the closed-loop descriptor system is stable with a desired $H_{\infty}$ disturbance attenuation level. Furthermore, the outcome of the proposed switching tracking control problem is formulated as a set of linear matrix inequalities (LMIs). Finally, simulation results demonstrate the effectiveness of the proposed design method.

• 한국국방경영분석학회지
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• 제35권3호
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• pp.47-59
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• 2009

A hybrid Genetic Algorithm is applied to military resource allocation problem. Since military uses many resources in order to maximize its ability, optimization technique has been widely used for analysing resource allocation problem. However, most of the military resource allocation problems are too complicate to solve through the traditional operations research solution tools. Recent innovation in computer technology from the academy makes it possible to apply heuristic approach such as Genetic Algorithm(GA), Simulated Annealing(SA) and Tabu Search(TS) to combinatorial problems which were not addressed by previous operations research tools. In this study, a hybrid Genetic Algorithm which reinforces GA by applying local search algorithm is introduced in order to address military optimization problem. The computational result of hybrid Genetic Algorithm on Missile Interceptor Allocation problem demonstrates its efficiency by comparing its result with that of a simple Genetic Algorithm.

• 한국군사과학기술학회지
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• 제9권2호
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• pp.143-151
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• 2006

This paper investigates effects of reaction control jet on the aerodynamic performance of generic interceptor missile operating at supersonic flight condition. Parallelized CFDS code is used as a viscous flow solver. The generic interceptor missile configuration composed of a long and slender body and fixed tail fins. The behavior of normal force, axial force and pitching moment characteristics at altitude conditions corresponding to 10 km is studied according to the given control jet conditions, different angle of attacks based on the analysis of aerodynamic characteristics.