• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.121-124
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• 2007

This article describes a function and structure of access network equipment under BcN environment. Access network until now have constructed separately to offer voice, data service. However, simplifies network structure, function that can do traffic concentration, subscriber certification, individual charging, QoS according to service and routing is required in BcN. In this paper, compare method offering by separate system with existing access network and method that offer integrating function inside system for structure of suitable access network to BcN and search structure of access network equipment for desirable access network of hereafter. Composition of this paper is as following. In Chapter 2, establishment history and structure of access network until present. In Chaprte 3, define suitable requirement and functions to BcN. And compare structure for access net work that is new with present. Last Chapter 4, suggests direction of structure of BcN access network and concludes conclusion.

• 동력기계공학회지
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• 제16권1호
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• pp.78-83
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• 2012

The authors suggest the algorithm for the static analysis of a three dimensional solid structure by using the finite element-transfer stiffness coefficient method (FE-TSCM) and the hexahedral element of the finite element method (FEM). MATLAB codes were made by both FE-TSCM and FEM for the static analysis of three dimensional solid structure. They were applied to the static analyses of a very thick plate structure and a three dimensional solid structure. In this paper, as we compare the results of FE-TSCM with those of FEM, we confirm that FE-TSCM introducing the hexahedral element for the static analysis of a three dimensional solid structure is very effective from the viewpoint of the computational accuracy, speed, and storage.

• Wind and Structures
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• 제31권5호
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• pp.381-392
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• 2020

Despite that the failure of sign structure may not have disastrous consequence, its sheer number still ensures the need for rigorous safety standard to regulate their maintenance and construction. During its service life, a sign structure is subject to extensive wind load, sometimes well over its permissible design load. A fragility analysis of a sign structure offers a tool for rational decision making and safety evaluation by using a probabilistic framework to consider the various sources of uncertainty that affect its performance. Wind fragility analysis was used to determine the performance of sign structure based on the performance of its connection components. In this study, basic wind fragility concepts and data required to support the fragility analysis of the sign structure such as sign panel's parameters, connection component's parameters, as well as wind load parameters were presented. Fragility and compound fragility analysis showed disparity between connection component. Additionally, reinforcement of the connection system was introduced as an example of the utilization of wind fragility results in the retrofit decision making.

• 항공우주시스템공학회지
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• 제7권2호
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• pp.8-14
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• 2013

When launch vehicles are manufactured, one of the key points is a design of lightweight structure for reducing costs. Isogrid structure was designed to solve this topic, and many researches were carried out about buckling load because compression load is mainly applied to them. Recently, many studies are also being carried out about FEM model geometry of isogrid structure. The reason is that isogrid structure depends on size of ribs so it is difficult to modify about small changes in rib pattern. In this study, 1/8 model of cylindrical isogrid structure model was developed to analyze buckling behavior. Through parameter study, buckling analysis were performed to analyze buckling load and buckling mode depending on size of ribs.

• Wind and Structures
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• 제29권2호
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• pp.99-110
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• 2019

This paper provides a simple numerical method to determine the optimal parameters of tuned mass damper (TMD) and viscoelastic dampers (VEDs) in frame structure for wind vibration control considering the soil-structure interation (SSI) effect in frequency domain. Firstly, the numerical model of frame structure equipped with TMD and VEDs considering SSI effect is established in frequency domain. Then, the genetic algorithm (GA) is applied to obtain the optimal parameters of VEDs and TMD. The optimization process is demonstrated by a 20-storey frame structure supported by pile group for different soil conditions. Two wind resistant systems are considered in the analysis, the Structure-TMD system and the Structure-TMD-VEDs system. The example proves that this method can quickly determine the optimal parameters of energy dissipation devices compared with the traditional finite element method, thus is practically valuable.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.73-78
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• 2000

This paper describes the effect of span-to-depth ratio, which describes aspect of cell formed with top diaphragm steel plate, on capacity in composite steel-concrete structure of sandwich system. The span-to-depth ratio \ulcorner load-carrying mechanism and load-distribution capacity of structure. Therefore, stress levels of members and load-resis\ulcorner of system vary according to span-depth ratio. In this study, numerical nonlinear analysis was performed to various ratio for two types(MA, MB) composite structure of sandwich system to analyze the influence of span-to-depth ratio or, behavior. The difference of load-carrying mechanism and stress of members results from analysis results, then bas\ulcorner differences, the effects of span-to-depth ratio on shear capacity, flexural capacity and load-resistance capacity were analyze effects on failure mode and ductility were briefly. As a results of this study, as span-to-depth ratio increases, \ulcorner bottom steel plate and concrete lower. This implies an increase in effective flexural and shear capacity. Therefore lo\ulcorner capacity of structure improves as span-to-depth ratio increases, Especially, the effect is greate in shear than flexural span-to-depth ratio increases, this difference between flexural and shear capacity may change failure mode and ductility. span-to-depth ratio increases capacity increases more than flexural capacity, we should expect that structural behavior mode gradually change from shear to flexural and ductility of structure gradually improves.

• 한국시뮬레이션학회논문지
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• 제28권3호
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• pp.1-9
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• 2019

주식 시장, 인구 동향, 전염병 확산 예측, 도로교통체계 개발과 같이 다양한 분야에서 활용되고 있는 에이전트 기반 시뮬레이션 분야의 에이전트는 응용분야에 따라 각기 다른 형태로 발전되어왔다. 하지만 다학제 융합적 협력 요구되는 문제의 해결에 있어서 확장 가능한 형태의 에이전트 구조가 필요하며 이를 지원할 에이전트 모델링 및 시뮬레이션 환경이 필요하다. 본 연구는 다양한 분야의 에이전트를 수용하기 위하여 공통구조를 체계요소구조와 이산사건시스템형식론을 활용하여 명세할 수 있는 방법을 제시하고, 제시된 명세방법을 지원할 수 있는 개발 환경인 SESManager를 제안한다. 제안된 환경은 계층적으로 에이전트 구조를 정의하고 에이전트를 합성할 수 있도록 함으로써 사용자의 시뮬레이션 목적에 맞게 에이전트 시뮬레이션을 수행할 수 있도록 돕는다.

• Geomechanics and Engineering
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• 제2권1호
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• pp.1-18
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• 2010

The analysis of structure response and design of buried structures subjected to dynamic destructive loads have been receiving increasing interest due to recent severe damage caused by strong earthquakes and terrorist attacks. For a comprehensive design of buried structures subjected to blast loads to be conducted, the whole system behaviour including simulation of the explosion, propagation of shock waves through the soil medium, the interaction of the soil with the buried structure and the structure response needs to be simulated in a single model. Such a model will enable more realistic simulation of the fundamental physical behaviour. This paper presents a complete model simulating the whole system using the finite element package ABAQUS/Explicit. The Arbitrary Lagrange Euler Coupling formulation is used to model the explosive charge and the soil region near the explosion to eliminate the distortion of the mesh under high deformation, while the conventional finite element method is used to model the rest of the system. The elasto-plastic Drucker-Prager Cap model is used to model the soil behaviour. The explosion process is simulated using the Jones-Wilkens-Lee equation of state. The Concrete Damage Plasticity model is used to simulate the behaviour of concrete with the reinforcement considered as an elasto-plastic material. The contact interface between soil and structure is simulated using the general Mohr-Coulomb friction concept, which allows for sliding, separation and rebound between the buried structure surface and the surrounding soil. The behaviour of the whole system is evaluated using a numerical example which shows that the proposed model is capable of producing a realistic simulation of the physical system behaviour in a smooth numerical process.

• 한국항공우주학회지
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• 제49권8호
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• pp.617-626
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• 2021

비행체의 초음속 비행 중 고온 환경에서의 열 거동은 비행체의 열 구조 설계에 중요하다. 본 연구에서는 전역-국부 다중 디지털 이미지 상관기법을 사용하여 노치 구조물의 전 영역의 열변형 및 응력집중 현상에 대해 관찰/분석하였다. 다중 DIC 시스템은 2D DIC 시스템과 3D DIC 시스템으로 구성되었다. 가열 챔버를 이용하여 노치 시편을 가열하였으며 여러 온도에서 다중 DIC 시스템을 사용하여 구조물의 변형 이미지를 촬영하고 분석하였다. 다중 DIC 기법을 사용하여 노치 시편의 전 영역 변형률과 노치 부위의 응력집중 현상을 계측/분석하였으며 ABAQUS^TM 프로그램을 이용하여 노치 시편에 대해 유한요소해석을 진행하고 실험결과와 비교 분석하였다. 본 연구를 통해 다중 DIC 시스템의 열변형 계측과 응력 집중 현상의 연구 분석에서의 활용 가능성을 보여주었다.

• 한국자동차공학회논문집
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• 제15권3호
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• pp.63-71
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• 2007

During the design phase of a product, reliability and design engineers are called upon to evaluate the reliability of the system, The question of how to meet target reliability for the system arises when estimated reliability or cost is inadequate. This then becomes a problem of reliability allocation and system structure design. This study proposes the optimization methodology to achieve target reliability with minimum cost through construction of the cost function of system. In cost function, total cost means the sum of initial cost, repair cost and maintenance cost. This study constructs optimization problem about system structure design and reliability allocation using cost function. This problem constructed is solved by Multi-island Genetic Algorithm(MIGA), and applies to urban transit brake system. Current brake system of the urban transit is series system. Series system is the simplest and perhaps one of the most common system, but it demands high reliability and maintenance cost because all components must be operating to ensure system operation. Thus this study makes a comparative study by applying k-out-of-n system to brake system. This methodology presented can be a great tool for aiding reliability and design engineers in their decision-makings.