• Journal of Ecology and Environment
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• 제33권4호
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• pp.275-288
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• 2010

Ecological modeling faces some unique problems in dealing with complex environment-organism relationships, making it one of the toughest domains that might be encountered by a modeler. Newer technologies and ecosystem modeling paradigms have recently been proposed, all as part of a broader effort to reduce the uncertainty in models arising from qualitative and quantitative imperfections in the ecological data. In this paper, evolutionary computation modeling approaches are introduced and proposed as useful modeling tools for ecosystems. The results of our case study support the applicability of an algal predictive model constructed via genetic programming. In conclusion, we propose that evolutionary computation may constitute a powerful tool for the modeling of highly complex objects, such as river ecosystems.

• 한국게임학회 논문지
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• 제9권5호
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• pp.127-136
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• 2009

본 논문에서 3DARModeler 라는 증강현실 환경에서의 3D 모델링 시스템에 대해서 제시 한다. 이 시스템은 3D 객체(모델)를 만들기 위해 객체 호출, 텍스쳐 적용, 애니메이션, 광원추정, 그림자 등의 기능들이 포함된 간단한 3D Studio Max라고 볼 수 있다. 3DARModeler는 3D 모델을 만들기 위한 효과적이고 편리한 상호작용 방법들을 제시한다. 3DARModeler 시스템의 주사용자는 컴퓨터 그래픽, 모델링 기술에 관한 많은 지식을 갖추지 않은 비전문가들을 대상으로 한다. 사용자들은 기본 객체를 선택, 객체들의 속성 부여, 여러 객체들의 결합을 통하는 방법으로 사용자가 실세계에서 직접 모델링을 하는 것과 같이 간단하고 직관적인 방법의 모델링을 가능하도록 한다.

• 한국건설관리학회논문집
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• 제5권5호
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• pp.151-162
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• 2004

Current methods for construction site modeling employ large, expensive laser range scanners that produce dense range point clouds of a scene from different perspectives. Days of skilled interpretation and of automatic segmentation may be required to convert the clouds to a finished CAD model. The dynamic nature of the construction environment requires that a real-time local area modeling system be capable of handling a rapidly changing and uncertain work environment. However, in practice, large, simple, and reasonably accurate embodying volumes are adequate feedback to an operator who, for instance, is attempting to place materials in the midst of obstacles with an occluded view. For real-time obstacle avoidance and automated equipment control functions, such volumes also facilitate computational tractability. In this research, a human operator's ability to quickly evaluate and associate objects in a scene is exploited. The operator directs a laser range finder mounted on a pan and tilt unit to collect range points on objects throughout the workspace. These groups of points form sparse range point clouds. These sparse clouds are then used to create geometric primitives for visualization and modeling purposes. Experimental results indicate that these models can be created rapidly and with sufficient accuracy for automated obstacle avoidance and equipment control functions.

• 한국정보통신학회논문지
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• 제6권5호
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• pp.768-776
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• 2002

멀티미디어, 인터넷 환경에서 서버 시스템의 활용이 일반화됨에 따라, 시스템에 저장된 모든 자료의 보안을 위한 권한 부여나 접근 제어와 같은 상위 수준의 보안 메카니즘이 요구되는 현실이다. 또한 분산 환경에서는 시스템내에 저장된 정보들의 정형화된 스키마의 부재, 비체계성 등으로 인하여 보다 복잡한 체계의 보호기술이 필요하게 되었다. 본 논문에서는 일반적인 접근제어 방식을 고찰, 분석하고 기본적인 모델링을 정리하여 설명하였고, RBAC(Role-Based Access Control) 모델링의 모듈들을 분리하고 각 모듈들에 대한 역할을 할당한 후, 기존의 접근제어 모델링과 RBAC 모델링을 혼합 사용하여 새로운 접근제어 모델링을 제시한다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제13권2호
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• pp.54-61
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• 2008

수평 혹은 경사 형태 특수 정호 양수량에 대한 시공간적 수위 강하를 지하수 수치 모델링을 활용하여, 평가하였다. 지하수 수치 모델링은 상용 프로그램인 FEFLOW(version 5.1)의 1차원 선형 불연속 특징 요소를 활용하여 수행되었으며, 수치해의 검증을 위해 Zhan과 Zlotnik(2002)이 제안한 연속된 점 형태 배출원 배열 방식 준 해석해와 비교하였다. 비교 검증 결과, 수치해와 준해석해는 최대 수위 강하가 나타나는 양수 최인접부를 제외하고는 거의 일치한 형태를 보여주었다. 검증된 수치적 방법을 이용하여, 강변여과 방식 취수가 검토되는 현장에 대한 수위강하를 정량적으로 평가할 수 있었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권6호
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• pp.101-113
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• 2016

To properly manage and remediate groundwater contaminated with chlorinated hydrocarbons such as trichloroethylene (TCE), it is necessary to assess natural attenuation processes of contaminants in the aquifer along with investigation of contamination history and aquifer characterization. This study evaluated natural attenuation processes of TCE at an industrial site in Korea by delineating hydrogeochemical characteristics along the flow path of contaminated groundwater, by calculating reaction rate constants for TCE and its degradation products, and by using geochemical and reactive transport modeling. The monitoring data showed that TCE tended to be transformed to cis-1,2-dichloroethene (cis-1,2-DCE) and further to vinyl chloride (VC) via microbial reductive dechlorination, although the degree was not too significant. According to our modeling results, the temporal and spatial distribution of the TCE plume suggested the dominant role of biodegradation in attenuation processes. This study can provide a useful method for assessing natural attenuation processes in the aquifer contaminated with chlorinated hydrocarbons and can be applied to other sites with similar hydrological, microbiological, and geochemical settings.

• Smart Structures and Systems
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• 제19권5호
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• pp.553-565
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• 2017

Structural modeling of unencapsulated ionic polymer metal composite (u-IPMC) actuators that are used for flapping the insect scale-flapping wing of micro air vehicles (FMAV) in dry environmental conditions is carried out. Structural modeling for optimization of design parameters for retention of water, maximize actuation performance and to study the influence of water activity on the actuation characteristics of u-IPMC is explored for use in FMAV. The influence of equivalent weight of Nafion polymer, cations, concentration of cations, pre-treatment procedures on retention of water of u-IPMCs and on actuation parameters, flapping angle, flexural stiffness and actuation displacement are investigated. IPMC designed with Nafion having equivalent weight 900-1100, pre-heated at $30^{\circ}C$ and with sodium as the cations is promising for optimum retention of water and actuation performance. The actuation parameters while in operation in dry and humid environment with varying water activity can be tuned to desirable frequency, deflection, flap angle and flexural stiffness by changing the water activity and operational temperature of the environment.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 춘계 학술대회논문집
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• pp.2-2
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• 2007

• 정보과학회지
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• 제25권11호
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• pp.32-38
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• 2007

• 한국대기환경학회지
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• 제15권3호
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• pp.335-366
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• 1999