• Structural Engineering and Mechanics
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• v.43 no.1
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• pp.15-30
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• 2012

A damped Timoshenko beam element is introduced for the DOF-efficient forced vibration analysis of beam-like structures coated with viscoelastic damping layers. The rotary inertia as well as the shear deformation is considered, and the damping effect of viscoelastic layers is modeled as an imaginary loss factor in the complex shear modulus. A complex composite cross-section of structures is replaced with a homogeneous one by means of the transformed section approach in order to construct an equivalent single-layer finite element model capable of employing the standard $C^{0}$-continuity basis functions. The numerical reliability and the DOF-efficiency are explored through the comparative numerical experiments.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.156-165
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• 1998

This paper proposes a systematic design methodology for the Takagi-Sugeno(TS) model based fuzzy control system with guaranteed stability and additional constraints on the closed-loop pole location. These combined two objectives are formulated as a system of LMIs(Linear Matrix Inequalities). Since LMIs intrinsically reflect constraints, they tend to offer more flexibility for combining various constraints on the closed-loop system. To demonstrate the usefulness of the proposed design methodology it is applied to the requlation problem of a nonlinear magnetic bearing system. Simulation results show that the proposed LMI-based design methodology yields not only maximized stability boundary but also the desired transient responses.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.1 no.2
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• pp.183-191
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• 1997

A neural network-based algorithm for the static weapon-target assignment (WTA) problem is Presented in this paper. An optimal WTA is one which allocates targets to weapon systems such that the total expected leakage value of targets surviving the defense is minimized. The proposed algorithm is based on a Hopfield and Tank's neural network model, and uses K x M processing elements called binary neuron, where M is the number of weapon platforms and K is the number of targets. From the software simulation results of example battle scenarios, it is shown that the proposed method has better performance in convergence speed than other method when the optimal initial values are used.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.109-113
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• 2006

This paper presents an in-flight alignment method for strapdown inertial navigation systems based on the line-of-sight information. Unlike the existing methods, the proposed method utilizes only the 2-axis angle measurements of the onboard image sensor and does not require any explicit range measurements between the vehicle and landmarks. To improve the accuracy of all the position, velocity, and attitude estimates through the in-flight alignment, an error model of the image-sensor-aided SDINS is derived. A simulation study demonstrates that the accuracy of SDINS can be improved by the line-of-sight information only.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.238-240
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• 2003

현재 국방부에서는 국방정보체계간의 상호운용성을 보장하기 위해 아키텍처 산출물을 쉽고 일관성 있게 개발할 수 있는 국방 아키텍처 프레임워크를 개발하고 있다. 따라서 개발된 아키텍처 산출물을 저장하여 재사용하고 국방 전반의 아키텍처 정보의 교환, 비교, 통합을 용이하게 하는 핵심아키텍처데이터모델의 개발이 필요하다. 핵심아키텍처데이터모델은 국방 아키텍처 프레임워크에서 도출된 데이터 요구사항을 통해 엔티티를 추출하고 관계를 정의하였으며 실사례를 통해 엔티티를 검증하였다. 이를 통해 전군의 아키텍처에 대한 공통의 데이터 모델을 제공하여 국방정보체계에 대한 통합적인 정보자원관리와 상호운용 및 통합을 향상시킬 수 있다.

• Journal of Sensor Science and Technology
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• v.25 no.6
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• pp.418-422
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• 2016

A filtering algorithm based on the decentralized moving average Kalman filter with uncertainties is proposed in this paper. The proposed filtering algorithm presented combines the Kalman filter with the moving average strategy. A decentralized fusion algorithm with the weighted sum structure is applied to the local moving average Kalman filters (LMAKFs) of different window lengths. The proposed algorithm has a parallel structure and allows parallel processing of observations. Hence, it is more reliable than the centralized algorithm when some sensors become faulty. Moreover, the choice of the moving average strategy makes the proposed algorithm robust against linear discrete-time dynamic model uncertainties. The derivation of the error cross-covariances between the LMAKFs is the key idea of studied. The application of the proposed decentralized fusion filter to dynamic systems within a multisensor environment demonstrates its high accuracy and computational efficiency.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.358-359
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• 2017

본 논문에서는 민방위 대피시설을 조사한 결과를 바탕으로 대피시설에 적용하고 있는 화생방 설비의 개념을 분석하여, 우리의 실정 및 재난 특성에 따라 적절히 대응할 수 있는 대피시설의 설계 기준(안)을 도출하여, 획일화된 방호개념을 탈피한 대피시설의 구축 기반을 설정하기 위해 새로운 건물 내 대피시설(SIP) 개념을 도입하여, 일반 국민이 화생방관련 민방위 사태에 대응하여 사용할 수 있는 대피시설 계획의 설계 기준을 마련하는 것이다. 전체 대피시설 중 0.1%를 차지하고 있는 화생방 대피시설의 비율이다. 개소수로는 29개소이며, 이 시설은 일반 주민은 사용할 수 없는 충무지휘용 대피시설이다. 이는 화생방 재난 및 사고 발생 시 일반 주민들은 대피할 공간이 전혀 없다는 것을 의미한다. 본 연구에서는 미국의 대피시설 계획 설계내용을 검토하고 국내 시설과 비교하여 대피시설의 성능을 비교 검증하고 화생방 대피시설의 일반적/기술적 구축 조건 모델을 구성하였다.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.3
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• pp.425-435
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• 2017

In this work, an overview of flow diagnosis in a shock tunnel is made by means of using established techniques that are easy to setup, economical to arrange, and simple to measure. One flow condition was considered having Mach number of 6 at the nozzle-exit, regarded as freestream. Measured aerothermodynamic data such as shock wave speed, wall static and total pressures, surface heat flux, and shock stand-off distance ahead of test model showed good agreement with calculation. This study shows an overall procedure of flow diagnosis in a shock tunnel in a single manuscript. Outcomes are thought to be useful in the field of education and also in a preliminary stage of high-speed vehicle design and tests, that need to be performed within a short time with decent accuracy.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.387-394
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• 2016

This paper proposes a new disturbance observer(DOB). The purpose of the DOB is to realize the plant performing like a model in the presence of disturbances which come from external environment and inherent nonlinearities and uncertainties in the plant. It is shown that the proposed DOB compensates those disturbances, nonlinearities and uncertainties, effectively. And it is theoretically proved that the proposed DOB can be guaranteed its stability for the stable plant. Its availability is shown by applying the DOB to the stabilization platform for EOTS(Electro Optical Tracking System).

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.4
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• pp.520-527
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• 2017

In this study, the experimental methods are compared for obtaining the parameters of the Johnson-Cook constitutive model. The parameters used for numerical simulation are very important in making an accurate estimation of numerical simulation. So, the testing method of obtaining the parameters is also very important. We compared the difference of conventional method, compression method and tensile method of AISI-4340 steel at various strain rate by using MTS, SHPB and SHTB. Taylor impact test and M&S were carried out to compare differences among these three types of JC constitutive parameter.