• Journal of Korea Water Resources Association
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• v.51 no.4
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• pp.347-354
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• 2018

In urban areas, runoff flow is drained through sewer networks as well as surface areas. Therefore, it is very important to consider sewer networks as a component of hydrological drainage processes when conducting urban inundation modelling. However, most researchers who have implemented urban inundation/flood modelling, instinctively simplified the sewer networks without the appropriate criteria. In this research, a 1D-2D fully coupled urban inundation model is applied to estimate the influence of sewer network simplification on urban inundation modelling based on the dendritic network classification. The one-dimensional (1D) sewerage system analysis model, which was introduced by Lee et al. (2017), is used to simulate inlet and overflow phenomena by interacting with surface flow. Two-dimensional (2D) unstructured meshes are also applied to simulate surface flow and are combined with the 1D sewerage analysis model. Sewer network pipes are simplified based on the dendritic network classification method, namely the second and third order, and all cases of pipes are conducted as a control group. Each classified network case, including a control group, is evaluated through their application to the 27 July 2011 extreme rainfall event, which caused severe inundation damages in the Sadang area in Seoul, South Korea. All cases are compared together regarding inundation area, inflow discharge and overflow discharge. Finally, relevant criterion for the simplification method is recommended.

• Journal of the Korea Computer Graphics Society
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• v.4 no.1
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• pp.1-10
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• 1998

The idea of level-of-detail based on multiresolution model is gaining popularity as a natural means of handling the complexity regarding the realtime rendering of virtual environments. To generate an effective multiresolution model, we should capture the prominent visual features in the process of simplifying original complex model. In this paper, we incorporate view dependent features such as silhouette features and backface features, to the generation process of multiresolution model. To capture the view directional parameter, we propose multiresolution view sphere. View sphere maps the directional relationship between object surface and the view. Using the view sphere, coherence in the directional space is mapped into spatial coherence in the view sphere. View sphere is generated in multiresolution fashion to simplify the object. To access multiresolution view sphere efficiently, we devise quad tree for the view sphere. We also devise a mechanism for realtime simplification process using proposed view sphere. Using proposed mechanism, regenerating simplified model in realtime is effectively done in the order of number of rendered vertices.

• Journal of Digital Convergence
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• v.16 no.6
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• pp.85-93
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• 2018

The Latent Growth Modeling(LGM) is known as the arising analysis method of longitudinal data and it could be classified into unconditional model and conditional model. Unconditional model requires estimated value of intercept and slope to complete a model of fitness. However, the existing LGM is in absence of a structured methodology to estimate slope when longitudinal data is neither simple linear function nor the pre-defined function. This study used Sequential Pattern of Association Rule Mining to calculate slope of unconditional model. The applied dataset is 'the Youth Panel 2001-2006' from Korea Employment Information Service. The proposed methodology was able to identify increasing fitness of the model comparing to the existing simple linear function and visualizing process of slope estimation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.8 no.2
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• pp.9-16
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• 1990

This is a geodetic study on the the shoreline changes occurred by the facilities constructed in the beach. There are emperical, hydrological and numerical methods in predicting of the shorline changes. Numerical method is the most suitable method in the field of geodesy. There are many predicting models. This study adopted one-line model because it has a few hydrological factor and simplify the natural phenomena. This study established the ideal seawall boundary condition, applied the explicit model and the implicit model in the Dongsan harbour in East Sea, and could predict the optimum seawall position for protection of shore. The results are following ; Seawall protect shore of which input angle of wave is below 20$^\circ$, a ratio of wave height bleak/line does not effect in shoreline changes. The implicit model is accuracy but can not predict longtime change. But the explicit model is the opposite of the implicit model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.1 no.2
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• pp.69-74
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• 2000

The area of informatization in small business industry consists of production automation. management automation, and network. This paper mainly deals with the management automation which uses management information systems. Functionally speaking, there are four broad categories such as manufacturing, marketing. human resource, and accounting. However, since most of small business industries emphasize more on the manufacturing and marketing, an integrated information system with these two core processes has been developed based on object-oriented methodology. The system, one of the important steps in the stage model this paper proposes, has not only simple and essential features ensuring easy implementation, but also friendly interface and good modularity based on the object-oriented paradigm.

• Journal of Industrial Convergence
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• v.20 no.12
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• pp.195-202
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• 2022

Underground Geospatial Information Map Management System(UGIMMS) integrates various underground facilities in the underground space into 3D mesh data, and supports to check the 3D image and location of the underground facilities in the mobile app. However, there is a problem that it takes a long time to run in the app because various underground facilities can exist in some areas executed by the app and can be seen layer by layer. In this paper, we propose a deep learning-based K-means vertex clustering algorithm as a method to reduce the execution time in the app by reducing the size of the data by reducing the number of vertices in the 3D mesh data within the range that does not cause a problem in visibility. First, our proposed method obtains refined vertex feature information through a deep learning encoder-decoder based model. And second, the method was simplified by grouping similar vertices through K-means vertex clustering using feature information. As a result of the experiment, when the vertices of various underground facilities were reduced by 30% with the proposed method, the 3D image model was slightly deformed, but there was no missing part, so there was no problem in checking it in the app.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.313-324
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• 2010

IPTV has been launched to provide a simple convergence service with broadcast and communication, and now it is evolving to support personalized service capabilities according to user's requirements. The paper presents DSON architecture and its control model to provide personalized features and user centric capability in IPTV services over service overlay network. Furthermore, the paper introduces DSON based service models on community IPTV and home IPTV service model.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.1765-1768
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• 2002

최근 들어 웹사이트 개인화(Web Personalization)에 관한 연구가 활발히 진행되고 있다. 웹 개인화는 클러스터링과 같은 데이터 마이닝 기법을 이용하여 개개의 사용자에게 가장 흥미를 갖을만한 URLs의 집합을 예측하는 것이라 할 수 있다. 기존에는 웹 트랜잭션을 클러스터링 하기 위해서 사용자의 방문여부에 따라 트랜잭션을 비트벡터(bit vector)로 표현하였다. 하지만 이것은 웹 트랜잭션의 클러스터링에 있어서 사용자의 흥미를 배제하고 단순히 방문여부만을 반영하게 된다. 이에 본 논문에서는 사용자의 흥미도(Interestingness)를 반영할 수 있도록 보완된 웹 트랜잭션 모델을 제시하고 제안된 트랜잭션 모델을 적용한 유사도 비교방법을 제안한다. 그리고 성능평가를 통하여 제안한 방법이 기존 방법에 비해 클러스터링의 정확성을 높임을 보인다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.647-649
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• 2000

개념-논리 스키나 설계의 목적은 개념 스키마를 사용 가능한 데이터의 구조화와 제약사항 모델화를 위한 기능들을 가능한 후 효과적으로 표현하는 것이다. 스키마 변환은 이러한 표현을 구현 언어나 데이터베이스와는 독립적인 차원에서 고려할 수 있도록 해준다. 개념-논리 스키마로의 변환에 프리미티브 변환을 적용함으로써 얻을 수 있는 이점은 개념 스키마에 나타난 정보를 손실 없이 구현 모델에 반영할 수 있게 한다는 것이다. 본 논문에서는 다단계 보안 응용을 위한 일반화 계층구조의 스키마 변환에서 발생할 수 있는 프리미티브 변환을 논의한다. 이러한 변환은 다단계 보안 응용의 개념 논리와 설계 단계에 대한 질적 향상을 기할 수 있는 기본적인 도구의 토대가 될 수 있으며 또한 이를 적용함으로써 설계 과정을 변환의 작은 단위로 생각할 수 있게 해 줌으로서 설계 과정을 단순화할 수 있다.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1331-1334
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• 2006

동영상에서의 움직임 추적은 이전 프레임에서 얻어낸 정보를 이용할 수 있다는 점에서 프레임간의 연결 관계에 기반한 움직임 추적이 가능하다. 그러나 사람의 신체는 고정된 형태를 가지고 있지 않기 때문에 프레임 간의 단순한 연결 관계만으로 사람의 자세를 추정하고 움직임을 추적하는 것은 매우 어려운 문제이다. 본 논문에서는 구성요소에 기반한 인체 모델을 이용하여 이전 프레임에서 찾은 블랍들을 연속된 프레임에서 찾은 블랍들로 연결함으로써, 동영상에서 사람의 자세를 추적하는 방법을 제안한다. 주어진 모델에 따라 이전 블랍은 대응되거나, 여러 블랍으로 나뉘거나, 다른 블랍들과 결합되어 사라지거나, 새로 생성되는 등의 4 가지 경우로 나뉘어 질 수 있는데, 각 경우에 대한 처리 방안을 제안하였다. 제안된 방법은 인체들과 블랍들의 리스트 처리를 간단하게 할 뿐만 아니라, 추적의 전처리 과정으로 블랍화를 옳게 수행해야 하는 부담을 덜어주어 과도한 블랍화와 부족한 블랍화 등의 문제를 해결할 수 있다.