• Composites Research
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• 제15권6호
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• pp.1-7
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• 2002

VARTM공정에서는 수지유동을 빠르게 하기 위해 투과촉진층이 사용되는데 투과촉진층과 섬유층 사이의 수지 속도차가 크다. VARTM제품은 길이에 비해서 두께가 얇으나 두 가지 다른 유통 매질 사이에 발생하는 lead-lag 유통을 관찰하기 위해서는 두께 방향을 고려한 3차원해석이 요구된다. 그런데 3차원 해석에 있어서 계산 시간이 문제가 된다. 일반 PC로 절점수가 많은 3차원 문제를 해석하려면 오랜 시간이 소요되므로 비실용적이다. 그래서 본 연구에서는 dual-scale 기법을 도입하여 전체 영역은 2.5차원으로 해석하고 주요한 관심 영역만을 3차원으로 해석하였다. 2.5차원 시뮬레이션만으로 예측하기 어려운 lead-lag 유동과 같은 특이한 유동 경향을 국부적인 3차인 해석을 통해서 발견학 수 있었다. 본 연구에서 개발된 global-local 해석기술은 일반 PC에서 적당한 계산 시간 내에 균일하지 않은 유동 매질 사이를 지나는 유동흐름의 특성 분석에 효과적으로 사용될 수 있다.

• 대한수학교육학회지:학교수학
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• 제4권2호
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• pp.161-192
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• 2002

This paper investigated the teaching and teaming of contents-related graphing in Korean secondary textbooks and suggested the improved methods of graph instruction through this analysis. reification-the case of function, In Harel, G., Dubinsky(Eds.), The Concept of Function : Aspects of Epistemology and Pedagogy Textbooks are analyzed from the viewpoint of the proportion of graphing contents, their sequencing, the proportion of each domain in graphing activities (interpretation vs. construction, quantitative vs. qualitative aspect, local vs. global aspect) and tasks (prediction, translation, scaling), and the difference in the graphing contents between the sixth and the seventh curriculum. This analysis demonstrates that graphing contents are increasing in textbooks, therefore the high school textbooks appear in almost every content area. The graphing activities concentrate on the construction, the quantitative aspects, and the local aspects, and are gradually focusing on the interpretation and global aspects of high school textbooks. Furthermore, most of graphing tasks favor translation. In contrast, the current seventh curriculum includes a balance of interpretation and construction activities and has more global aspects than the sixth curriculum based textbooks; however, the qualitative approach still rarely appears. For the graphing tasks, translation is still prevalent, but the importances of prediction tasks based on graph have increased in comparison with the sixth curriculum textbooks. Further, the seventh curriculum based textbooks are designed to stimulate more dynamic graphing instruction by introducing new tools such as graphing calculators and computer software. We suggest that the qualitative and global aspects should be emphasized in early graph instruction, a variety of graph activities in realistic contexts should be performed, and educational technology such as graphing calculator and computer can be efficient to implement these ideas.

• IEIE Transactions on Smart Processing and Computing
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• 제5권1호
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• pp.49-54
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• 2016

Regarding global and local factors of a set of features, a given single image or multiple images is a common approach in image processing. This paper introduces an application of an adaptive version of non-local filter whose original version searches non-local similarity for removing noise. Since most images involve texture partner in both foreground and background, extraction of signified regions with texture is a challenging task. Aiming to the detection of visual attention regions for images with texture, we present the contrast analysis of image patches located in a whole image but not nearby with assistance of the adaptive filter for estimation of non-local divergence. The method allows extraction of signified regions with texture of images of wild life. Experimental results for a benchmark demonstrate the ability of the proposed method to deal with the mentioned challenge.

• 아태비즈니스연구
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• 제14권4호
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• pp.357-370
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• 2023

Purpose - This study examined the influence relationships between the impacts of tourism development, local attachment, and resident involvement and local residents' support and pro-environmental behavior intentions in Jeju Island. Design/methodology/approach - A questionnaire was distributed to the Jeju Island residents and 373 samples were used for the analysis. Findings - The results showed that the perceived positive impact of tourism development has a positive effect on local residents' support, while the negative impact has a negative effect. Local attachment has no significant effect on local residents' support, while local involvement positively affects local residents' support. The positive impact of tourism development has a negative effect on pro-environmental behavior intention, while the perceived negative impact has a positive effect. Finally, when analyzing the relationship between local attachment, local involvement, and local support for eco-friendly behavior intention, it was found that they all have a positive effect. Research implications or Originality - Theoretical and managerial implications and suggestions for future research are discussed.

• Journal of applied mathematics & informatics
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• 제6권3호
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• pp.823-834
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• 1999

The present paper deals with the problem of nonselective harvesting in a partly infecte prey and predator system in which both the suseptible prey and the predator follow the law of logistic growth and some preys avoid predation by hiding. The dynamical behaviour of the system has been studied in both the local and global sense. The optimal policy of exploitation has been derived by using Pontraygin's maximal principle. Numerical analysis and computer simulation of the results have been performed to inverstigate the global properties of the system.

• 한국측량학회지
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• 제36권1호
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• pp.17-24
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• 2018

DEM (Digital Elevation Model) is a useful dataset which represents the earth surface. Beside many applications, production and frequent update of DEM is a costly task. Recently global satellite based DEMs are available which has huge potential for application. To check the accuracy, this study compares two global DEMs: AW3D30 (Advanced Land Observing Satellite World 3D 30m) and SRTM30 (Shuttle Radar Topography Mission Global 30m) with reference resampled LiDAR DEM 30m in a test area around Chuncheon, Korea. The comparison analysis was based on statistics of each DEM, their difference, profiles, slope, basin and stream orders. As a result, it is found that SRTM30 and AW3D30 were much similar but inconsistent in the test area compared to the LiDAR30 DEM. In addition, SRTM30 shows less difference with LiDAR30 compared to the AW3D30 DEM. But, DEMs should be very carefully examined for area which has temporal or season changes. For basin and stream analysis, global DEMs can be used only for regional scale analysis not local large scales.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2011년도 정기 학술대회
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• pp.557-560
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• 2011

In the present paper, the sloshing resistance performance of an LNG carrier insulation system is evaluated by fluid-structure interaction (FSI) analysis. For this analysis, the arbitrary Lagrangian Eulerian (ALE) method is adopted to accurately calculate the structural behavior induced by internal LNG motion of a KC-1 type LNG carrier cargo tank. In addition, the global-local analysis method is introduced to reduce computational time and cost. The global model is built from shell elements to reduce the sloshing analysis time. The proposed novel analysis techniques can potentially be used to evaluate the structural integrity of LNG carrier insulation systems.

• 한국강구조학회 논문집
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• 제12권1호통권44호
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• pp.45-54
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• 2000

본 연구는 반복되는 중간단계의 구조설계과정에 연동되는 근사 재해석 모델을 비교 평가하고, 특히 설계변수가 크게 변화할 때도 일정한 정확도를 유지하여 전체 설계과정에 효율성과 신뢰성을 함께 줄 수 있는 안정된 모델을 찾는다. 이를 위해 대형 프레임구조를 대상으로 설계변수 그룹의 갯수와 변화량을 달리하면서 최대 변위값을 정해와 비교하여 정확도 및 신뢰성을 검토하고, CPU 연산시간 비교를 통해 효율성을 시험한다. 예제를 통하여 부분근사화는 가장 간편하고 빠르기는 하나 설계의 면화가 극히 적은 특정한 경우에만 유용한 반면 전역근사화는 기저벡터를 효과적으로 취할 경우 설계 변화량이 클 때에도 비교적 높은 정확도를 유지하나 효율성이 떨어지는 취약점을 갖고 있다. 이들에 비해 전역-부분근사화는 어느 경우에나 높은 정확성과 효율성을 아울러 갖추고 있음을 보여준다. 이 방법들을 구조 재설계 과정에 연계할 때 설계정보에 따라 혼용하므로써 효율성을 증대시킬 수 있다.

• 한국콘텐츠학회논문지
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• 제19권12호
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• pp.38-56
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• 2019

기후변화의 지역적 광역성과 장기성으로 기후변화 문제는 일개 국가의 노력만으로는 해결할 수 없는 전지구적 난제로 자리 잡고 있다. 따라서 수직적으로 전세계(global), 지역(regional), 국가(national), 지방(local) 수준의 수직적 거버넌스가 중요하다. 또한 각 수준에서 정부, 기업, 민간의 수평적 거버넌스가 조화롭게 작동할 때 복잡한 기후변화문제에 대한 해결 실마리를 얻을 수 있다. 본 연구에서는 1990년부터 2018년까지 29년간 일간신문에서 기후변화라는 주제어를 가진 약 24,000건의 기사에 나타난 기후변화에 대한 수직적·수평적 거버넌스와 이슈트렌드 등을 분석하였다. 분석결과 우리나라에서는 수직적 측면에서 글로벌 기후변화 이슈를 중앙정부는 적극적으로 참여하고 있으나, 동북아와 같은 지역적 논의는 거의 없었다. 수평적 측면에서는 정부 중심의 논의가 주류를 이루고 있고 민간 시민단체의 참여나 기업의 참여는 부족하였다. 향후 기후변화에 효과적으로 대응하기 위해서는 수직적 측면에서는 지역적 협력에 대한 논의와 함께 기후변화가 직접적으로 행동에 옮겨질 수 있는 지방수준에서 실질적인 논의가 활발히 이루어져야 한다. 또한 수평적인 측면에서는 개발시대의 관주도적 태도에서 벗어나 시장메커니즘을 적극적으로 활용할 수 있는 방안과 시민사회의 참여를 유도할 수 있는 방안이 마련되어야 한다. 이를 위해 기후변화대응 기본법 등의 제정을 통한 제도적 정비를 제안하였다.

• Journal of Computing Science and Engineering
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• 제8권4호
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• pp.199-206
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• 2014

The ant colony optimization (ACO) algorithm is a new heuristic algorithm that offers good robustness and searching ability. With in-depth exploration, the ACO algorithm exhibits slow convergence speed, and yields local optimization solutions. Based on analysis of the ACO algorithm and the genetic algorithm, we propose a novel hybrid genetic ant colony optimization (NHGAO) algorithm that integrates multi-population strategy, collaborative strategy, genetic strategy, and ant colony strategy, to avoid the premature phenomenon, dynamically balance the global search ability and local search ability, and accelerate the convergence speed. We select the traveling salesman problem to demonstrate the validity and feasibility of the NHGAO algorithm for solving complex optimization problems. The simulation experiment results show that the proposed NHGAO algorithm can obtain the global optimal solution, achieve self-adaptive control parameters, and avoid the phenomena of stagnation and prematurity.