• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.346-346
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• 2017

기후변화에 따른 기상이변의 동시다발적인 발현은 농촌 지역의 홍수 발생 빈도를 증가시키고 있다. 현재의 기후시스템은 과거의 강우빈도를 기준으로 산정한 설계기준을 벗어나는 강우 사상을 빈번하게 발생시키므로 설계변수의 불확실성을 보다 합리적인 방법으로 정량화할 필요가 있다. 본 연구의 목적은 기후변화에 대응하여 확률론을 이용한 농업용 저수지의 홍수 취약성을 산정하는 데 있다. 먼저 홍수 취약성 해석에 필요한 과거와 미래 수문 자료를 수집하고 전처리 과정을 통해 해석에 적합한 자료로 구축하였다. 설계변수의 불확실성을 분석하기 위해 지속시간별 최대강우량, 유입 설계홍수량에 대해 부트스트랩 (bootstrap) 기법을 적용하여 자료를 재추출하였다. 부트스트 랩은 표본집단의 확률분포에 대해 가정을 하지 않고 표본집단의 통계적 특성을 이용하여 모집단의 통계적 추론을 할 수 있는 비모수적인 리샘플링 기법이다. 부트스트랩 추론은 표본집단의 추정치, 편의, 표준오차를 산정하고 신뢰구간을 추정한다. 부트스트랩 추론을 통해 산정하는 신뢰수준을 이용하여 농업용 저수지의 홍수 취약성을 산정하였다. 본 연구는 설계변수에 내재하는 불확실성을 부트스트랩 기법을 이용하여 정량화하고 확률적인 값을 가지는 홍수 취약성으로 산정하여 제시할 수 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.426-433
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• 2020

This study aimed to compare the pretreatment methods of phytoplankton for type approval of the Ballast Water Treatment System (BWMS). The International Maritime Organization (IMO) and the United States Maritime Police (USCG) use two different test methods for this purpose. To compare the two methods, a test for concentration and non-concentration was performed with cultured and natural phytoplankton, and samples from the land-based BWMS test. The extent of damages caused by the process of concentration varied between cultured and natural species, indicating differences depending on the physiological and morphological characteristics of the species. In the land-based test, in the control water with a high biological population, the number of non-concentrated samples was about twice as high as that of the concentrated samples. There was no distinct difference between the two methods in the treated water with a low biological population. Thus, although there is a difference between concentration and non-concentration for phytoplankton sampling, the concentration method can be applied as a method of evaluating BWMS performance. However, a method for evaluating whether live species in treated water may be lost or damaged during the concentration process of sampling should be developed and validated.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.312-312
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• 2011

All ship's ballast water should be inspected by administration after enter into force IMO BWM Convention. The purpose of the sampling device is to concentrate large amount of samples and to improve return rate of samples. It is composed of Concentration and Rinsing Part and optimized by the variety of tests. it is fully automated and therefore efficiently operated in ships.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.417-420
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• 2007

마이크로어레이는 생명과학 분야에서 사용되는 대규모의 유전자 발현정도를 동시에 측정할 수 있는 도구이다. 마이크로어레이 실험은 많은 양의 데이터를 생성하기 때문에, 자동화된 효과적인 분석기법이 필요하다. 이 논문에서는 약물의 영향 분석을 위해 약물의 투여량 및 투여후의 시간대별로 샘플을 추출하여, 마이크로어레이를 이용하여 유전자의 발현량을 분석하는 경우에, 약물에 대해서 반응하는 유전자를 추출하는 데이터 마이닝 기법을 제안한다. 제안한 방법에서는 유전자의 발현정도값을 이전 시간의 값을 기준값으로 하여 증가, 감소, 답보에 해당하는 기호로 매핑하여, 분석자가 원하는 패턴을 보이는 유전자를 추천한다. 한편, 유전자의 상호간에 많은 영향을 주고 받기 때문에 특정 약물을 투여할 때, 이에 직접적인 영향을 받는 것도 있지만, 이와는 전혀 상관없이 동작하는 것도 있기 때문에, 제안한 방법에서는 이러한 약물 투여와 유의성이 있을 가능성이 있는 유전자만을 전처리과정을 통해서 필터링하는 기법을 활용한다. 제안한 방법은 실제 약물 투여 실험 샘플에 대한 마이크로어레이 데이터에 적용하여 활용가능성을 확인하였다.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.263-268
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• 2021

The purpose of this study was to propose a model which is suitable for the actual delivery system by designing a fetal delivery hospital operation management and fetal health classification model. The number of deaths during childbirth is similar to the number of maternal mortality rate of 295,000 as of 2017. Among those numbers, 94% of deaths are preventable in most cases. Therefore, in this paper, we proposed a model that predicts the health condition of the fetus using data like heart rate of fetuses, fetal movements, uterine contractions, etc. that are extracted from the Cardiotocograms(CTG) test using a random forest. If the redundancy of the data is unbalanced, This proposed model guarantees a stable management of the fetal delivery health management system. To secure the accuracy of the fetal delivery health management system, we remove the outlier which embedded in the system, by setting thresholds for the upper and lower standard deviations. In addition, as the proportion of the sequence class uses the health status of fetus, a small number of classes were replicated by data-resampling to balance the classes. We had the 4~5% improvement and as the result we reached the accuracy of 97.75%. It is expected that the developed model will contribute to prevent death and effective fetal health management, also disease prevention by predicting and managing the fetus'deaths and diseases accurately in advance.

• Resources Recycling
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• v.21 no.4
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• pp.69-75
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• 2012

Destruction of HFC-134a from ELV (End of Life Vehicle) were determined in a gasification-melting demonstration system of municipal solid waste (100ton/day). The injection system has been developed for the uniform injection of HFC-134a to the gasification-melting system. The destruction characteristics of HFC-134a and analysis of exhaust gases have been performed. The destruction efficiency was 99.995% for HFC-134a feeding of 3 kg/hr and the exhaust gases such as CO, SOx, NOx, HCl and HF satisfied the environmental standards.

• Journal of KIISE
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• v.42 no.6
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• pp.769-780
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• 2015

Smoothing a digital curve by averaging its connected points is widely employed to minimize sharp changes of the curve that are generally introduced by noise. An appropriate degree of smoothing is critical since the area or features of the original shape can be distorted at a higher degree while the noise is insufficiently removed at a lower degree. In this paper, we provide a mathematical relationship between the parameters, such as the number of iterations, average distance between neighboring points, weighting factors for averaging and the moving distance of the point on the curve after smoothing. Based on these findings, we propose to control the smoothed curve such that its deviation is bounded particular error level as well as to significantly expedite smoothing for a pixel-based digital curve.

• Journal of Environmental Science International
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• v.20 no.1
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• pp.93-106
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• 2011

Physically-based resampling scheme for roughness coefficient of surface runoff considering the spatial landuse distribution was suggested for the purpose of effective operational application of recent grid-based distributed rainfall runoff model. Generally grid scale(mother scale) of hydrologic modeling can be greater than the scale (child scale) of original GIS thematic digital map when the objective basin is wide or topographically simple, so the modeler uses large grid scale. The resampled roughness coefficient was estimated and compared using 3 different schemes of Predominant, Composite and Mosaic approaches and total runoff volume and peak streamflow were computed through distributed rainfall-runoff model. For quantitative assessment of biases between computational simulation and observation, runoff responses for the roughness estimated using the 3 different schemes were evaluated using MAPE(Mean Areal Percentage Error), RMSE(Root-Mean Squared Error), and COE(Coefficient of Efficiency). As a result, in the case of 500m scale Mosaic resampling for the natural and urban basin, the distribution of surface runoff roughness coefficient shows biggest difference from that of original scale but surface runoff simulation shows smallest, especially in peakflow rather than total runoff volume.

• Journal of the Korea Computer Graphics Society
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• v.8 no.2
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• pp.9-14
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• 2002

In cases of densely occluded urban scenes, it is effective to determine the visibility of scenes, since only small parts of the scene are visible from a given cell. In this paper, we introduce a new visibility preprocessing method that efficiently computes potentially visible objects for volumetric cells. The proposed method deals with general 3D polygonal models and invisible objects jointly blocked by multiple occluders. The proposed approach decomposes volume visibility into a set of point visibilities, and then computes point visibility using hardware visibility queries, in particular HP_occlusion_test and NV_occlusion_query. We carry out experiments on various large-scale scenes, and show the performance of our algorithm.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.238-245
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• 2013

Gesture recognition has been widely one of the research areas for natural user interface. This paper presents a novel gesture recognition method using tree classification and multiclass SVM(Support Vector Machine). In the learning step, 3D trajectory of human gesture obtained by a Kinect sensor is classified into the tree nodes according to their distributions. The gestures are resampled and we obtain the histogram of the chain code from the normalized data. Then multiclass SVM is applied to the classified gestures in the node. The input gesture classified using the constructed tree is recognized with multiclass SVM.