• Title/Summary/Keyword: 완전 동적

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Agent-based Mediator System (에이전트 기반 협상 시스템)

  • 이금주;김분희;김삼택;김영찬
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.04a
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    • pp.343-345
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    • 2001
  • 전자상거래 기술은 현실 세계에 좀더 완전하고 최적화된 상황과 조건을 요구하고 있다. 초기의 쇼핑 에이전트는 사용자의 모든 요구조건과 특성을 만족시키는 대신에 단순히 판매자가 제시하는 가격 기반 비교만을 하는 문제점이 있다. 본 논문은 기존의 쇼핑 에이전트가 갖고 있는 판매자 자격 중심 비교와 지능화와 자동화의 부족이라는 문제점을 극복하기 위해 각 상품에 따른 특성이 반영될 수 있는 동적 거래 알고리즘을 적용한 협상시스템을 제안하고, 이 알고리즘을 이용한 시스템을 개발하였다.

Dynamic Response of Underground Openings Considering the Effect of Water Saturation (지하수의 영향을 고려한 지하공동구조체의 동적응답)

  • 김선훈;김광진
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.14 no.3
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    • pp.391-399
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    • 2001
  • Three-dimensional dynamic analysis of underground openings subjected to explosive loadings considering the effects of water saturation is carried out in this study. The surrounding rock mass is assumed to be the limestone with 13.5% of porosity. Two calculations are compared using as identical explosive charge; the first in dry rock of 13.5% porosity, the second in the identical rock, but in a fully saturated condition. It is shown that velocity, displacement, and stress time histories are higher in saturated rock than those in dry rock through numerical studies. It is also shown that underground openings in saturated rock masses could be significantly more vulnerable to the potential damages associated with shear failure than those in dry medium.

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Dynamic Verification Methodology of User Code in AddSIM Environment (AddSIM 환경에서의 사용자 코드 동적 검증 방법론)

  • Yang, Jiyong;Choi, Changbeom
    • Journal of the Korea Society for Simulation
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    • v.28 no.1
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    • pp.41-47
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    • 2019
  • Defense simulation is actively used to test various weapon systems and evaluate their effectiveness. The AddSIM environment is a simulation framework designed to support the weapon systems dealt with in defense simulation from an integrated point of view and is designed for reuse and scalability. Models used in AddSIM require base model structure fidelity and verification of user code area. Therefore, this paper describes the dynamic verification method used for completeness of models used in AddSIM. For the dynamic verification of user code, the specification method and the verification algorithm are described. Also, we introduce the prototype of the dynamic verifier implemented based on verification specification method and algorithm. The case study analyzes the verification results based on the simulation example implemented in AddSIM environment.

Estimaion of the sintering and forging characteristics of the W/Cu nanocomposite powders produced by the spray conversion process (Spray conversion 법으로 제조된 W/Cu 나노복합분말의 소결특성 및 단조특성 평가)

  • 김태형;노준웅;김은표
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2002.11a
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    • pp.36-36
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    • 2002
  • 최근 한국기계연구원에서 개발된 Mechanochemical process (MCP)는 Spray conversion 법에 의하여 나노크기의 W/Cu 복합 분말을 제조하는 방법으로서, 현재 (주)나노테크에서 산업화를 위한 시험/개발이 진행 중이다. 이 방법에 의하여 W /1 0 ~ 40wt. %Cu 조성의 초미렵 W/Cu 복합 분말의 양산화가 가능하게 됨으로써, 나노복합분말을 사용한 초미립 W/Cu 합금의 소결 제조 연구 역시 나 노태크에서 분말사업화와 동시에 수행되고 있다. 현재 Spray conversion 법으로 제조되고 있는 W/Cu 나노복합분말 및 그 소결체는 Cu의 조성범 위에 따라 민수용 및 군수용 제품으로의 적용이 시도되고 있으며, 각기 특성향상을 목표로 각 적용 분야에서 요구되는 제반 성능에 대한 검토가 이루어지고 있다. 특히 군수용의 목적으로 사용될 경우, 정적 및 동적부하상태에서 재료의 균일한 변형이 가장 중요한 특성이다. 현 개발품의 경우, 일반 W 빛 Cu 원료에 비하여 상대적으로 높은 순도의 원료를 사용하였기 때문에 분말 및 소재상태 에서의 순도가 높아서, 연성을 저하시키는 것으로 알려진 기지상내 합금원소 또는 interface 게재물 이 존재할 가능성이 매우 낮다. 또한 초미립 W 입자들과 Cu 상의 혼합도가 극대화된 상태이기 때문에 상대적으로 저옹에서도 완전치밀화된 미세조직을 얻을 수 있는데, 이는 분말상태의 균일한 미세구조를 유지할 수 있으며, 동시에 W 업자간의 과도한 neck 형성을 방지함으로써 기계적 변형시 재료의 연성 향상이 기대된다. 이러한 W/Cu 나노복합분말 소결체의 특성은 균일한 밀도분포와 동시에 과도한 동적 부하상태에서 균일한 변형이 보장되어야만 하는 특정 군수용 목적에 잘 부합하는 것으로 판단된다. 본 고에서는 상기한 W/Cu 나노복함분말을 사용하여 균일한 미세구조를 가지는 완전치밀화된 소결재를 제조하는 과정과 제조된 소결재를 향후 군수용 제품에 척용시키기 위하여 진행된 단조특성에 대한 연구결과틀을 재료의 미세구조척 관점에서 논의하였다.

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Dynamic Behavior of 2D 8-Story Unbraced Steel Frame with Partially Restrained Composite Connection (합성반강접 접합부를 갖는 2차원 8층 비가새 철골골조의 동적거동)

  • Kang, Suk Bong;Lee, Kyung Taek
    • Journal of Korean Society of Steel Construction
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    • v.19 no.5
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    • pp.503-513
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    • 2007
  • The seismic responses of a building are affected by the connection characteristics that have effects on structural stiffness. In this study, push-over analysis and time history analysis were performed to estimate structural behavior of 2D eight-story unbraced steel structures with partially restrained composite connections using a nonlinear dynamic analysis program. Nonlinear $M-{\theta}$characteristics of connection and material inelastic characteristics of composite beam and steel column were considered. The idealization of composite semi-rigid connection as fully rigid connection yielded an increase in initial stiffness and ultimate strength in the push-over analysis. In time history analysis, the stiffness and hysteretic behavior of connections have effects on base-shear force, maximum story-drift and maximum moment in beams and columns. For seismic waves with PGA of 0.4 g, the structure with the semi-rigid composite connections shows the maximum story-drift with less than the life safety criteria by FEMA 273 and no inelastic behavior of beam and column, whereas in the structure with rigid connections, beams and columns have experienced inelastic behaviors.

Structure Pruning of Dynamic Recurrent Neural Networks Based on Evolutionary Computations (진화연산을 이용한 동적 귀환 신경망의 구조 저차원화)

  • 김대준;심귀보
    • Journal of the Korean Institute of Intelligent Systems
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    • v.7 no.4
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    • pp.65-73
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    • 1997
  • This paper proposes a new method of the structure pruning of dynamic recurrent neural networks (DRNN) using evolutionary computations. In general, evolutionary computations are population-based search methods, therefore it is very useful when several different properties of neural networks need to be optimized. In order to prune the structure of the DRNN in this paper, we used the evolutionary programming that searches the structure and weight of the DRNN and evolution strategies which train the weight of neuron and pruned the net structure. An addition or elimination of the hidden-layer's node of the DRNN is decided by mutation probability. Its strategy is as follows, the node which has mhnimum sum of input weights is eliminated and a node is added by predesignated probability function. In this case, the weight is connected to the other nodes according to the probability in all cases which can in- 11:ract to the other nodes. The proposed pruning scheme is exemplified on the stabilization and position control of the inverted-pendulum system and visual servoing of a robot manipulator and the effc: ctiveness of the proposed method is demonstrated by numerical simulations.

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Nonlinear Dynamic Analysis of Space Steel Frames (공간 강뼈대 구조물의 비선헝 동적 해석)

  • Kim Seung-Eock;Cuong Ngo-Huu;Lee Dong-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.18 no.4 s.70
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    • pp.395-404
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    • 2005
  • This paper presents a reliable numerical procedure for nonlinear time-history analysis of space steel frames subjected to dynamic loads. Geometric nonlinearities of member (P-$\delta$) and frame (P-$\Delta$) are taken into account by the use of stability functions in framed stiffness matrix formulation. The gradual yielding along the member length and over the cross section is included by using a tangent modulus concept and a softening plastic hinge model based on the New-Orbison yield surface. A computer program utilizing the average acceleration method for the integration scheme is developed to numerically solve the equation of motion of framed structure formulated in an incremental form. The results of several numerical examples are compared with those derived from using beam element model of ABAQUS program to illustrate the accuracy and the computational efficiency of the proposed procedure.

Application of Energy Dissipation Capacity to Earthquake Design (내진 설계를 위한 에너지 소산량 산정법의 활용)

  • 임혜정;박홍근;엄태성
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.6
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    • pp.109-117
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    • 2003
  • Traditional nonlinear static and dynamic analyses do not accurately estimate the energy dissipation capacity of reinforced concrete structure. Recently, simple equations which can accurately calculate the energy dissipation capacity of flexure-dominated RC members, were developed in the companion study. In the present study, nonlinear static and dynamic analytical methods improved using the energy-evaluation method were developed. For nonlinear static analysis, the Capacity Spectrum Method was improved by using the energy-spectrum curve newly developed. For nonlinear dynamic analysis, a simplified energy-based cyclic model of reinforced concrete member was developed. Unlike the existing cyclic models which are the stiffness-based models, the proposed cyclic model can accurately estimate the energy dissipating during complete load-cycles. The procedure of the proposed methods was established and the computer program incorporating the analytical method was developed. The proposed analytical methods can estimate accurately the energy dissipation capacity varying with the design parameters such as shape of cross-section, reinforcement ratio and arrangement, and can address the effect of the energy dissipation capacity on the structural performance under earthquake load.

Aeroelastic Analysis of Rotorcraft in Forward Flight Using Dynamic Inflow Model (동적 유입류 모델을 이용한 회전익기 전진비행 공탄성 해석)

  • Lee, Joon-Bae;Yoo, Seung-Jae;Jeong, Min-Soo;Lee, In;Kim, Deog-Kwan;Oh, Se-Jong;Yee, Kwan-Jung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.4
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    • pp.297-305
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    • 2011
  • In this study, the aeroelastic analysis of rotorcraft in forward flight has been performed using dynamic inflow model to handle unsteady aerodynamics. The quasi-steady airload model based on the blade element method has been coupled with dynamic inflow model developed by Peters and He. The nonlinear steady response to periodic motion is obtained by integrating the full finite element equation in time through a coupled trim procedure with a vehicle trim for stability analysis. The aerodynamic and structural characteristics of dynamic inflow model are validated against other numerical analysis results by comparing induced inflow and blade tip deflections(flap, lag). In order to validate aeroelastic stability of dynamic inflow model, lag damping are also compared with those of linear inflow model.

Prediction for Liquefaction and Lateral Flow on Non-plastic Silt (비소성실트지반의 액상화 및 측방유동량 예측)

  • Yang, Taeseon;Song, Byungwoong
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.11
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    • pp.65-70
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    • 2011
  • It is well known all much information for evaluation on possibility of liquefaction and lateral flow for sand over the world. Recently, it is started to be known that liquefaction happens on non-plastic silt, too. But cyclic and post-cyclic characteristics for non-plastic silt is a few familiar to the world. Specially, it is not aware of the estimating method for lateral flow on non-plastic silt. The main purpose in this paper is to propose the evaluation for liquefaction and lateral flow on non-plastic silt. The method used in this research is that possibility for liquefaction on non-plastic silt was evaluated with cyclic direct simple shear test, and then residental strength was estimated with static shear test. Through the test results liquefaction on non-plastic silt is well not happened but strength decreases rapidly with increasing shear stress. With the proposed method it can be evaluated possibility of liquefaction and propose lateral flow.