• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2000년도 학술발표회 논문집
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• pp.28-36
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• 2000

A TIN, Triangulated Irregular Network, based topographic modeling method and a distributed rainfall-runoff model using the topographic representation is presented. In the TIN based topographic representation, a watershed basin is modeled as a set of contiguous non-overlapping triangular facets: the watershed basin is subdivided according to streamlines to deal with water movement one-dimensionally; and each partitioned catchment is approximated to a slope element having a quasi-three-dimensional shape by using cubic spline functions. On an approximated slope element, water movement is represented by combined surface-subsurface kinematic wave equations considering a change of slope gradient and slope width. By using the distributed rainfall-runoff model, the effects of spatial variability of soil properties on runoff response are examined.

• 한국정밀공학회지
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• 제16권9호
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• pp.48-53
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• 1999

In this paper, a practical method for design and machining of cycloid gear was investigated. Based on the proposed method, a systematic program was developed for automatically designing the tooth profiles of epicycloid and hypocycloid gears for the case fo one difference between the number of teeth of cycloid gear and the number coordinates of tooth profiles and pressure angles. The error analysis between cycloid curve and Biarc curve was performed to show the effective method of equidistant partitioning of cycloid curve so that efficient method of Biarc curve fitting was also proposed for the partitioned curve.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.1370-1375
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• 2001

Substructure coupling or component mode synthesis may be employed in the solution of dynamic problems for structure. The model is partitioned into several subdomains. and a generalized Craig-Bampton representation is derived. In this paper the mode sets(normal modes. constraint modes) have been employed for model reduction. A generalized model reduction procedure has been described. Those reduction methods which adapt constraint modes have been described in detail. As examples. a flexible structure and a 10 DOF damped system are analyzed. Comparison with a conventional reduction method based on a complete model has been made via eigenpairs and dynamic responses.

• 한국측량학회지
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• 제37권5호
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• pp.323-330
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• 2019

Radiometric normalization with multi-temporal satellite images is essential for time series analysis and change detection. Generally, relative radiometric normalization, which is an image-based method, is performed, and histogram matching is a representative method for normalizing the non-linear properties. However, since it utilizes global statistical information only, local information is not considered at all. Thus, this paper proposes a histogram matching method considering local information. The proposed method divides histograms based on density, mean, and standard deviation of image intensities, and performs histogram matching locally on the sub-histogram. The matched histogram is then further partitioned and this process is performed again, iteratively, controlled with the wasserstein distance. Finally, the proposed method is compared to global histogram matching. The experimental results show that the proposed method is visually and quantitatively superior to the conventional method, which indicates the applicability of the proposed method to the radiometric normalization of multi-temporal images with non-linear properties.

• 천문학회지
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• 제52권2호
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• pp.49-55
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• 2019

The New Vacuum Solar Telescope (NVST) is the largest solar telescope in China. When using CCDs for imaging, equal-thickness fringes caused by thin-film interference can occur. Such fringes reduce the quality of NVST data but cannot be removed using standard flat fielding. In this paper, a correction method based on multi-scale decomposition and adaptive partitioning is proposed. The original image is decomposed into several sub-scales by multi-scale decomposition. The region containing fringes is found and divided by an adaptive partitioning method. The interference fringes are then filtered by a frequency-domain Gaussian filter on every partitioned image. Our analysis shows that this method can effectively remove the interference fringes from a solar image while preserving useful information.

• 대한화학회지
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• 제30권5호
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• pp.465-474
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• 1986

농작물에 잔류되어 있는 11종의 유기인제 농약들을 추출하여 기체-액체 크로마토그래피로 동시에 분석함에 있어서 농작물별로 방해하는 다른 성분들을 분리, 제거하기 위한 액체-액체 분배와 컬럼크로마토그래피의 최적 조건을 찾고자 하였다. Acetone을 사용하여 농작물로부터 녹여낸 추출물에 포화 NaCl용액을 가하고 petroleum ether로 두 번 분배하여 농약들을 회수하였다. Activated carbon, magnesia 및 diatomaceous earth의 혼합 흡착제(1:2:4)를 충진시킨 컬럼에 petroleum ether에 분배된 추출물들을 넣고 methyl chloride로 용리시켰더니 가해준 농약의 82∼105%가 회수되었고 농작물에서 녹아나온 방해 성분들이 거의 제거되었다.

• 한국산림과학회지
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• 제99권5호
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• pp.706-710
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• 2010

Understanding of chemical composition and energy contents in tree is important to develope strategies of renewable energy policy to cope with climate change. Residual biomass as renewable energy source was evaluated and focused on the bark-containing branches. Chemical analysis studies were conducted for different part of yellow poplar (Liriodendron tulipifera), which were partitioned to inner bark, outer bark, small branches, medium branches, big branches and trunk. The variations in hydrophobic extractives, hydrophilic extractives, lignin, carbohydrate compositions, energy contents (higher heating value) and the ash content were determined. The inner and outer bark had higher ash content, hydrophobic and hydrophilic extractives content, and higher energy content than those of tree trunk. Polysaccharides content in inner and outer bark was quite lower than those of stem or branches. Based on the energy content of residual biomass, replacement of fossil fuel and greenhouse gas emission abatement were calculated.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1621-1621
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• 2001

The quality of sugarcane grown on the NE Australian tropical coast ($16^{\circ}$15'- $18^{\circ}$15' S Lat.) has declined markedly in the past seven years. This has been linked to dilution of mill-supply cane with increasing levels of non mature-stalk material consisting of leaves and sucker culms. The prime research objective was to examine the transition from the pre-harvest, in-field crop to harvested material sent for processing, in terms of quality and crop fraction proportions. A secondary objective was to quantify the effects of preharvest-season crop habit and culm condition on crop quality. Ten quadrat samples from each of 54 random crop sites (17 in 1999 and 37 in 2000), covering a wide range of variables (cultivar, crop class, and edaphic, topographic, climatic, and temporal factors) were collected immediately before harvest. Samples were partitioned into four fractions:- sound and unsound mature stalks (culms), sucker culms, and extraneous matter (leaves). Material harvested from each site was sampled and partitioned into four fractions:- sound and unsound billets (culm pieces), culm-spindle pieces, and leaf. In 2000, before harvest, 14 additional sites were sampled monthly, on three occasions, from March - June. Erect and non-erect culms were divided into sound and unsound classes. All samples were disintegrated and presented to a remote reflectance module of a scanning spectrophotometer using the BSES large cassette module. Near infra-red spectroscopic (NIS) analyses were developed for the rapid determination of quality components (Brix, commercial cane sugar (CCS), fibre, moisture, and polariscope reading). Calibrations for three material groups (culm (n = 639), non-culm (n = 496), and combined) were developed for all components using the 1999 data set. Two sub-sets (n = 178, and 190) of about 10% of the preharvest-season and harvest populations scanned in 2000 also were subjected to full routine laboratory analyses. The 1999 combined calibrations were excellent, but the culm calibrations produced consistently lower standard errors. Non-culm calibrations were marginally better than the combined for only CCS and pol. reading. Analysis of the 2000 culm data with calibrations using all 1999 and 2000 culm data resulted in better predictions relative to the 1999 culm calibrations. This also was true for the combined calibrations. Assessment of quality components in pre- and post-harvest sugarcane using NIS calibrations was more cost effective than using routine laboratory techniques. Outcomes from this NIS-facilitated research will have important economic consequences for the Australian sugarcane industry. Potential CCS present in mature culms is being discounted by dilution with leaves and sucker culms, threatening farm viability. The results question the efficacy of current harvesting technology. The CCS of harvested cane is improved only marginally over that of the in-field crop. Current harvesting technology requires either supplementary, innovative pre-mill processing or a design revolution to improve mill-supply cane quality, and therefore whole of industry economics. NIS-facilitated analyses, before the harvest season, highlighted the benefits of growing erect, sound crops. Loss of CCS then, can be minimized only by a combination of crop improvement and agronomic solutions, applied as part of sound on-farm management.

• 정보처리학회논문지D
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• 제14D권7호
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• pp.733-742
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• 2007

데이터 스트림이란, 빠른 속도로 지속적으로 생성되는 무한한 크기의 방대한 양의 데이터 집합으로 정의된다. 무한한 데이터 스트림에 비해 주어진 메모리 공간은 유한하게 한정되어 있어, 이러한 제약조건을 충족시키는 범위 내에서 일정 한도내의 정확도 오차를 허용하기도 한다. 또한, 변화하는 데이터 스트림 내의 최신 클러스터를 찾기 위해서는 데이터 객체의 저장없이 오래된 데이터 스트림 내의 정보들을 비중을 감소시킬 수 있어야 한다. 본 연구에서는 데이터 스트림 분석을 위한 데이터 스트림 격자 기반 클러스터링 기법을 제시한다. 주어진 초기 격자셀에 대해, 데이터 객체의 빈도가 높은 범위를 반복적으로 보다 작은 크기의 격자셀로 분할하여 최소 크기의 격자셀, 단위 격자셀을 생성한다. 격자 셀에서는 데이터 객체들의 분포에 대한 통계값만을 저장하여, 기존의 클러스터링 기법에 비해 데이터 객체에 대한 탐색없이 효율적으로 클러스터를 찾을 수 있다. 또한, 가용 메모리 공간에 따라 단위 격자셀의 크기를 조절하여 클러스터의 정확도를 최대화할 수 있어, 주어진 메모리 공간에 맞게 적응적으로 성능을 조절할 수 있다.

• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2511-2520
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• 2018

In this study, Multi-Radial Basis Function Support Vector Machine (Multi-RBF SVM) classifier is introduced based on a composite kernel function. In the proposed multi-RBF support vector machine classifier, the input space is divided into several local subsets considered for extremely nonlinear classification tasks. Each local subset is expressed as nonlinear classification subspace and mapped into feature space by using kernel function. The composite kernel function employs the dual RBF structure. By capturing the nonlinear distribution knowledge of local subsets, the training data is mapped into higher feature space, then Multi-SVM classifier is realized by using the composite kernel function through optimization procedure similar to conventional SVM classifier. The original training data set is partitioned by using some unsupervised learning methods such as clustering methods. In this study, three types of clustering method are considered such as Affinity propagation (AP), Hard C-Mean (HCM) and Iterative Self-Organizing Data Analysis Technique Algorithm (ISODATA). Experimental results on benchmark machine learning datasets show that the proposed method improves the classification performance efficiently.