• Food Science and Industry
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• v.52 no.1
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• pp.52-59
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• 2019

The present article covers a brief introduction on how repeated exposure design can be utilized for developing new food products. A generic consumer taste test which measures consumer acceptance in one trial may have limitation in predicting long-term acceptability of a product. The article describes the changes in food preference and choice during the course of life from infants to elderly. Then, several possible theories that proposes to delineate the underlying mechanisms for acquiring the liking for food is introduced. The article also discusses general experimental design, case studies which adopted repeated exposure design, the limitations and rapid test methods to predict long-term acceptance.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.352-358
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• 2006

우리나라 연안은 동해안을 제외한 대부분 지역이 저지대 완경사의 지형구조와 천해로 형성되어 태풍, 해일, 해수범람으로 해마다 인명, 시설물 파손, 침식 등 반복적인 피해가 발생하는 자연재해취약지역이다. 그러나 애년 발생하는 자연재해 방지를 위해 복구위주의 대책 마련에 중점을 두고 있는 상황이며, 재해 발생시 피해를 최소화 할 수 있는 종합적 재해방지연구는 미흡한 실정이다. 이에 본 연구에서는 피해예방 및 방재 정책수립시 의사결정지원을 위하여 Web상에서 실시간으로 피해예측지역 추출이 가능한 기법을 개발하고자 하였다. 이를 위해 고해상 위성영상기반의 재해관련 주제도를 제작하고 육상과 해상부분을 통합한 3차원 지형 구축을 통하여 실세계와 유사한 지형환경 DB를 구축하였다. 아울러 3차원 범람시뮬레이션을 통하여 재해발생시 위험지역을 실시간으로 파악함으로써 피해가능지역 표출이 가능한 시스템을 개발하였으며, 이를 통해 재해상황에 따른 피해를 최소화 할 수 있는 기반을 마련하고자 하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.5
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• pp.375-380
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• 2007

The nonlinear aerodynamic analysis of wing with control surface is performed using the frequency-domain panel method. To take into consideration the nonlinear aerodynamic characteristics of wing an iterative decambering approach is introduced. The iterative decambering approach uses the known aerodynamic characteristics of airfoil to calculate the aerodynamic characteristics of wing. The multi-dimensional Newton iteration is used to account for the coupling between the different sections of wing. The present method is verified by showing that it produces results that are in good agreement with experiments. The present method will be useful for the analysis of aircraft in the conceptual design because the present method can calculate promptly the nonlinear aerodynamic characteristics of wing with a few computing resources.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.11
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• pp.941-948
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• 2016

Textile composite materials have been widely applied in aerospace structures due to their various advantages such as high specific stiffnesses and strengths, better out-of-plane performances, impact and delamination resistances, and net shape fabrications. In this paper, a modified geometric model of repeating unit cell (RUC) is suggested based on the Naik's model for 2D plain weave textile composites. The RUC geometry is defined by various parameters. The proposed model considers another parameter which is a gap length between adjacent yarns. The effective stiffnesses are predicted by using the yarn slicing technique and stress averaging technique based on iso-strain assumption. And the stiffnesses of RUC are evaluated by adjusting the gap ratio and verified by comparing with Naik's model and experimental data for 2D plain weave composite specimens.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.525-535
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• 2018

If the frequency of a particular class is excessively higher than the frequency of other classes in the classification problem, data imbalance problems occur, which make machine learning distorted. Corporate bankruptcy prediction often suffers from data imbalance problems since the ratio of insolvent companies is generally very low, whereas the ratio of solvent companies is very high. To mitigate these problems, it is required to apply a proper sampling technique. Until now, oversampling techniques which adjust the class distribution of a data set by sampling minor class with replacement have popularly been used. However, they are a risk of overfitting. Under this background, this study proposes ROSE(Random Over Sampling Examples) technique which is proposed by Menardi and Torelli in 2014 for the effective corporate bankruptcy prediction. The ROSE technique creates new learning samples by synthesizing the samples for learning, so it leads to better prediction accuracy of the classifiers while avoiding the risk of overfitting. Specifically, our study proposes to combine the ROSE method with SVM(support vector machine), which is known as the best binary classifier. We applied the proposed method to a real-world bankruptcy prediction case of a Korean major bank, and compared its performance with other sampling techniques. Experimental results showed that ROSE contributed to the improvement of the prediction accuracy of SVM in bankruptcy prediction compared to other techniques, with statistical significance. These results shed a light on the fact that ROSE can be a good alternative for resolving data imbalance problems of the prediction problems in social science area other than bankruptcy prediction.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.267-271
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• 2004

2000년도 국내에 소개된 앙상블 유량예측은 한반도 유출특성을 고려한 예측시스템 구축을 위해 꾸준한 수정과 보완을 반복하며 약 5년간의 연구가 진행되었다. 앙상블 유량예측의 연구방향은 크게 예측의 정확성을 향상시키기 위한 이론적 인구와 수자원 계획과 관리에 활용될 수 있도록 GUI를 포함한 유량예측시스템을 구축하는 등의 실무적 연구가 함께 진행되고 있다. 앙상블 유량예측의 정확성을 향상시키기 위해 갈수기에 강우-유출모형의 모의능력을 개선해야 하며, 홍수기에는 기상예보를 효율적으로 이용해야 한다는 기본 전략을 수립하였다. 최근 강우-유출모형의 모의능력을 개선하기 위해 신경망 강우-유출모형을 구축하고, 기존 강우-유출모형의 모의결과를 보정하거나, 두개 이상의 모형을 결합함으로서 유량모의능력을 개선하여 갈수기 앙상블 유량예측 정확성을 향상시킬 수 있음을 증명하는 성과를 거둔 바 있다. 향후 앙상블 유량예측의 연구 방향은 기상예보자료의 적극적인 활용에 초점을 맞추고 있다. 최근 ENSO(El Nino Southern Occillation), PDI(Pacific Decadal Idex) 등 다양한 기후정보의 새로운 발견과 GCM 등 기후모형의 급속한 개선으로 기후 예측의 정확도가 높아지고 있는 추세이므로, 이를 이용하여 홍수기 앙상블 유량예측의 정확도 개선을 목표로 인구가 진행될 전망이다.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.154-156
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• 2002

정보화시대에 들어서면서 나날이 급증하는 데이터에 대한 재가용성을 위한 많은 연구가 이루어지고 있다 이러한 연구들은 의사결정지원, 예측, 추정 등의 분야에서 적용되고 있으나, 실생활에 활발히 적용되기까지 앞으로 많은 연구 및 개발이 요구된다. 이 논문에서는 수집된 데이터로부터 패턴을 추출하여 예측결과를 제공할 수 있는 시스템 모델과 모델에 적합한 점진적 규칙갱신 알고리즘을 제안하였다. 제안하는 예측 모델의 특징은 새로 입력되는 정보에 대한 반복 학습시 수치데이터에 대한 평균근사치 할당방법을 적용하여 규칙갱신을 용이하게 하였으며 각 클래스의 수치데이터에 대한 분류를 용이하도록 하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.12
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• pp.1048-1058
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• 2017

One of the failure mechanism of spaceborne electronics is a fatigue fracture on solder joint under launch random vibration. Thus, a necessity of early diagnosis through the fatigue life evaluation on solder joint arises to prevent such potential risk of failure. The conventional life prediction methods cannot assure the accuracy of life estimation results if the packaging type changes, and also requires much time and effort to construct the analysis model of highly integrated PCB with various packaging types. In this study, we performed life prediction of PCB based on a reliability and life prediction tool of sherlock as a new approach for evaluating the structural reliability on solder joint, and those prediction results were validated by fatigue tests. In addition, we also investigated an influence of solder height on the fatigue life of solder joint. These results indicated that the Sherlock is applicable tool for evaluating the structural reliability of spaceborne electronic.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.920-926
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• 2014

In this study, we applieorithmd the inverse analysis alg to the prediction of displacement shape in the example construction and verified the feasibility of suggested algorithm. For this purpose, as information processing knowledge in the field of IT is required and the need for convergence with the major is emerged, it is intended to try to apply the algorithm to the construction sector. Prediction of displacement shape is very important since it is related to the earth pressure of slurry wall and effecting on the safety of slurry wall after anchor removal. 3 levels of inverse analysis were applied to the slurry walls in 3 sites and compared the measured displacement shape with predicted displacement shape of the last excavation construction. As the predicted displacement shape was matched well with the measured one, the applied analysis algorithm in this study can be applied to the excavation construction.

• Economic and Environmental Geology
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• v.36 no.4
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• pp.313-320
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• 2003

Slope disaster is one of the repeated occurring geological disasters in rainy season resulting in about 23 human losses in Korea every year. The slope disaster, however, mainly depends on the spatial and climate properties. such as geology, geomorphology, and heavy rainfall, and, hence, the prediction or hazard analysis of the slope disaster is a difficult task. Therefore, GIS and various statistical methods are implemented for slope disaster analysis. In particular, GIS technique is widely used for the analysis because it effectively handles large amount of spatial data. The GIS technique. however, only considers the statistics between slope disaster occurrence and related factors, not the mechanism. Accordingly. an infinite slope model that mechanically considers the balance of forces applied to the slope is suggested here with GIS for slope disaster analysis. According to the research results, the infinite slope model has a possibility that can be utilized for landslide prediction and hazard evaluation since 87.5％ of landslide occurrence areas have been predicted by this technique.