• Earthquakes and Structures
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• 제7권3호
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• pp.333-347
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• 2014

Multi-scale model can take both computational efficiency and accuracy into consideration when it is used to conduct elasto-plastic seismic response analysis for complex steel bridges. This paper proposed a method based on pushover analysis of member sharing the same section pattern to verify the accuracy of multi-scale model. A deck-through type steel arch bridge with a span length of 200m was employed for seismic response analysis using multi-scale model and fiber model respectively, the validity and necessity of elasto-plastic seismic analysis for steel bridge by multi-scale model was then verified. The results show that the convergence of load-displacement curves obtained from pushover analysis for members having the same section pattern can be used as a proof of the accuracy of multi-scale model. It is noted that the computational precision of multi-scale model can be guaranteed when length of shell element segment is 1.40 times longer than the width of section where was in compression status. Fiber model can only be used for the predictions of the global deformations and the approximate positions of plastic areas on steel structures. However, it cannot give exact prediction on the distribution of plastic areas and the degree of the plasticity.

• 수산경영론집
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• 제41권1호
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• pp.25-52
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• 2010

The purpose of this paper is to suggest major strategies and necessary new projects for the medium- and long-term development of the Korean Fisheries Outlook Project. To suggest the Korean Fisheries Outlook Center with the above purpose, this paper employs Analytic Hierarchy Process analysis based on surveys obtained by special groups related with the KFOP. The survey is broadly composed of two goals; the medium- and long-term development directions and setting up of new furtherance projects. Each goal has upper and lower strategies respectively. The first goal, the medium- and long-term development directions, has four factors as upper strategies. The upper strategies are composed of accuracy, efficiency, timeliness, and political effectiveness of the fisheries outlook information. In addition, each upper strategy has three lower strategies respectively. For example, accuracy of the fisheries outlook information includes strength of data collection function, strength of satellite photography function, and strength of data analysis function. The second goal, setting up of new furtherance projects, has three factors as upper strategies. The upper strategies consist of accuracy promotion of outlook information using high-technique, field expansion of outlook species, and strength of analyzing function on oversea fisheries information. Each upper strategy has three lower strategies respectively. For instant, accuracy promotion of outlook information using high-technique has strength of information analysis function covered from production to consumption, strength of satellite information function, and structure of forecasting model on demand and supply by outlook species. The above upper and lower strategies were analytically drawn out through insightful interviews with special groups such as officials of the government, presidents of the producer and distributor groups, and researchers of the Korea Maritime Institute and other research institutes. As a result of AHP analysis, first, priorities of upper strategies with the medium- and long-term development directions are analyzed as accuracy, timeliness, political effectiveness, and efficiency in order. Also, priorities of all lower strategies reflecting priorities of upper strategies are examined as includes strength of data collection function on the fisheries outlook information, delivery of rapid information on outlook products for all people interested, strength of data analysis function on fisheries outlook information, strength of consumption outlook function on fish products, and strength of early warning system for domestic fish products in order. Second, priorities of upper strategies with the setting up of new furtherance projects are analyzed as accuracy promotion of outlook information using high-technique, field expansion of outlook species, and strength of analysis function on oversea fisheries information in order. In addition, priorities of all lower strategies reflecting priorities of upper strategies are examined as building up of forecasting model on demand and supply by outlook species, strength of information analysis function covering all steps from production to consumption, expansion of consumption outlook for consumers, strength of movement analysis function of oversea farming industry, and outlook expansion of farming species.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.388-391
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• 2003

In this study, the experimental results were simulated by using a nonlinear analysis programs IDARC 2D and RUAUMOKO 2D. These programs use a global Takeda-like model. The objectives of this study is to verify the correlation between the experimental and analytical responses of reinforced concrete (RC) frame and to provide the calibration to the available static inelastic analysis techniques. The evaluation of the accuracy of analytical simulation by IDARC 2D and RUAUMOKO 2D leads to the conclusion that the global behaviors can be, in general, simulated with limited accuracy in the linear analysis as detailing.

• 한국해양공학회지
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• 제11권1호
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• pp.3-9
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• 1997

In this paper, design sensivity of plate natural frequency is computed for thickness design variables. Once the variational equation is derived from Lagrange quation using the virtual displacement, governing energy bilinear form is obtained and sensivity equation is formulated through the first variation. Natural frequency is obtained using the commercial FEM code and the accuracy of sensivity is verified by finite difference. The accuracy of natural frequency and sensivity improves for the fine mesh model.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.12-18
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• 2002

For the analysis of Kirchhoff plate bending problems, a new meshless method is implemented. For the satisfaction of the C¹ continuity condition in which the first derivative is treated as another primary variable, Hermite interpolation is enforced on standard reproducing kernel particle method. In order to impose essential boundary conditions on solving C¹ continuity problems, shape function modifications are adopted. Through numerical tests, the characteristics and accuracy of the HRKPM are investigated and compared with the finite element analysis. By this implementation, it is shown that high accuracy is achieved by using HRKPM fur solving Kirchhoff plate bending problems.

• 한국운동역학회지
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• 제25권4호
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• pp.431-440
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• 2015

Objective : The purpose of this study was to investigate the relations between accuracy score and the motions which are performed in PyeongWon Poomsae, thereby developing objectivity in accuracy evaluations for Poomsae competitions. Method : The subjects were six male Poomsae players (age: $21.2{\pm}1.17yrs$, height: $173.4{\pm}3.95cm$, weight: $67.7{\pm}7.65kg$). A three-dimensional motion analysis was performed on the subjects using six high-speed cameras (60 frames/sec) and subjects' performed motions were evaluated by 5 evaluators. The entire Pyeong Poomsae was divided into 13 events and 9 phases; there were three pairs of symmetric phases among them: front kick & turning side kick phases (3PH, 3-1PH), arm motion & stance phases (4PH, 4-1PH), side kick with Hakdari-stance phases (5PH, 5-1PH). Performance time, change and range of COM, height of vertex, and foot of side kicks were analysed. The Data was analysed utilizing correlation analysis. Results : There was a positive correlation between accuracy score and the difference between right and left range of COM (X direction) at 4PH (r=0.921, p=0.009). Conclusion : The results of our study indicate that it is necessary to consider some of objective criterion such as performance time, COM range, and symmetrical movements in accuracy evaluations of Poomsae competitions.

• 대한공간정보학회지
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• 제19권4호
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• pp.109-118
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• 2011

본 연구는 지면 데이터�V을 이용하여 다중선형 회귀분석에 의한 평면방정식을 도출하여 전역필터링 한 것을 기준으로 전체 데이터�V을 이용하여 도출된 평면방정식으로 전역필터링 한 것과 가상격자별로 평면방정식을 도출하여 지역필터링을 수행한 결과를 분석하여 정확도를 평가하였다. 그 결과 지면 데이터�V을 이용한 전역필터링의 평균정확도를 기준으로 전체 데이터�V을 이용한 전역필터링의 정확도는 약 2~3%정도 떨어지고, 가상격자를 이용한 지역필터링의 정확도는 약 2~4% 떨어지는 것으로 나타났다. 특히 가상격자가 3~4cm일 때 기준자료와 약 2%의 정확도의 차이가 나타낸 것으로 보아 가상격자 사이즈를 라이다 스캔간격의 3~4배 크기로 지정하여 필터링 하는 것이 바람직 할 것으로 판단된다. 따라서 필터링의 적용방법에 따라 평균정확도가 차이가 발생하였으며, 향후 보다 다양한 실제지형을 선정하여 필터링의 정확도에 대한 연구가 필요할 것으로 생각된다.

• 대한토목학회논문집
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• 제39권1호
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• pp.239-246
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• 2019

드론사진측량(Drone photogrammetry)은 높은 정확도의 공간정보획득과 각종 모니터링 목적으로 활발히 활용되고 있다. 요구하는 정확도를 얻기 위한 드론사진측량 계획 시 경험 또는 기존의 사례를 참고하여 계획하는 경우가 일반적이나 불량한 정확도로 인하여 재 촬영하는 경우가 종종 발생한다. 요구하는 드론사진측량 처리결과의 공간정확도는 결과물의 종류에 관계없이 객관적인 평가의 수단이 되므로 신중히 결정할 필요가 있다. 따라서 드론사진측량의 프로젝트설계는 요구하는 공간정확도(3D positional accuracy)를 충족시키기 위해 촬영고도, 중복도, 지상기준점(GCP; Ground Control Point)의 수와 배치, 외부표정(EO; Exterior Orientation)요소에 대한 획득방법의 결정이 필요하다. 본 연구에서는 드론사진측량 정확도분석에 대한 기존 연구사례를 면밀히 분석하고 시험지역에 적용하여 검증하였으며 이 분석결과를 토대로 소규모지역 드론사진측량 프로젝트시의 설계지침을 마련하였다. 제시한 프로젝트설계지침은 완벽하지는 않지만 실무에 많은 도움이 될 수 있을 것을 기대하며 추후 종합적분석을 통한 설계지침이 마련된다면 완벽한 매뉴얼을 제공할 수 있을 것이다.

• 한국농공학회논문집
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• 제54권2호
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• pp.47-53
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• 2012

Recently many developed countries have used satellite images for classifying cropland areas to reduce time and efforts put into field survey. Korea also has used satellite images for the same purpose since KOMPSAT-2 was successfully launched and operated in 2006, but still far way to go in order to achieve the required accuracy from the products. This study evaluated the accuracy of the calculated croplands by using the objected classification method with various satellite images including ASTER, Spot-5, Rapid eye, Quickbird-2, Geo eye-1. Also, their usability and effectiveness for the cropland survey were verified by comparing with field survey data. As results. Geo eye-1 and Rapid eye showed higher accuracy to calculate the paddy field areas while Geo eye-1 and Quickbird-2 showed higher accuracy to calculate the upland field areas.

• 한국정보시스템학회:학술대회논문집
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• 한국정보시스템학회 2002년도 추계학술대회
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• pp.289-312
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• 2002

This study suggests the Link weight analysis approach to choose input variables and an integrated model to make more accurate bankruptcy prediction model. the Link weight analysis approach is a method to choose input variables to analyze each input node's link weight which is the absolute value of link weight between an input nodes and a hidden layer. There are the weak-linked neurons elimination method, the strong-linked neurons selection method in the link weight analysis approach. The Integrated Model is a combined type adapting Bagging method that uses the average value of the four models, the optimal weak-linked-neurons elimination method, optimal strong-linked neurons selection method, decision-making tree model, and MDA. As a result, the methods suggested in this study - the optimal strong-linked neurons selection method, the optimal weak-linked neurons elimination method, and the integrated model - show much higher accuracy than MDA and decision making tree model. Especially the integrated model shows much higher accuracy than MDA and decision making tree model and shows slightly higher accuracy than the optimal weak-linked neurons elimination method and the optimal strong-linked neurons selection method.