• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1787-1791
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• 2009

지표수의 유출과정을 설명하는 과정에서 중요인자이며, 생태수문학의 핵심변수이자 기상모형의 중요한 입력변수인 토양수분의 공간적 시간적 특징들은 강우 및 지하수와 토양수분간의 순환 구조를 규명하는데 매우 중요하다. 가장 널리 쓰이는 토양 수분 측정 장비인 TDR 장비 매설에 앞서 대상유역 선정에 대한 여러 가지 고려사항을 검토하고 수치지형 분석 등을 통한 사전분석을 실시하였다. 대상유역을 선정하기 위해서는 대상유역의 자료획득의 용이함, 지정학적, 시스템 운영적 측면에서의 가용성, 그리고 정밀측량 및 부수적요인 등 여러 요소의 고려가 요구된다. 청미천 유역을 대상으로 약 21 개의 대상후보사면을 정밀조사 하였으며, 충청북도 음성군 수레의산 청소련 수련원내의 산지 사면을 측정대상 사면으로, 지정학적 위치, 식생분포, 지질구조 및 심도 등의 토양특성의 고려를 통해서 선정하였다. 또한 대상 사면에 흐름 발생 및 분포를 계산하기 위해서 대상사면의 지표 및 기반암 표고를 정밀 측량하였으며, 기반암 또는 풍화대까지의 깊이를 실측하여 지표면 및 지하면의 수치지형 모형을 구축하였다. 대상사면 및 지하면에 대하여 표고수치지형모형(Digital Elevation Model:DEM)으로 도식한 후 흐름 발생 공간 분포를 계산하였다. 다양한 흐름 발생 알고리즘으로 기여사면적과 지형습윤지수를 계산하였다. 분배알고리즘의 의해 도출된 지형인자들로 인한 흐름발생 공간적 분포특성을 비교하여 센서의 매설 위치를 결정하였다. 센서 매설 위치에 대한 토양시료를 채취하여 토성을 분석한 결과는 미국 농무성 기준에 의한 분류로는 사양토로, 국제토양학회의 분류기준에 따르면 양토로 분류되었다. 대상사면의 유효입력강우를 확보하기위해서 개방공간인 수레의산 청소년수련원과 대상산림의 Canopy하부에 각각 강수측정 시스템을 설치하였고 약 6개월간 성공적으로 자료를 획득하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6C
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• pp.610-618
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• 2002

This paper presents a new image retrieval method that is based on color space and block region information. The color space information of images can be obtained by color binary set, and the block region information can be obtained by regional segmentation and feature. The candidate images are decided by comparing with color features and its binary set of query image and image feature database for retrieval. Particularly, it is possible that the retrieval using similarity-measurements has the weights of color spatial distribution arid its objective block region features. This retrieval method using color spatial and block region features is shown with the effectiveness on the result of implementation on image database with 6,000 images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11A
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• pp.1946-1956
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• 2001

In this paper, we propose a novel 2-D partial matching algorithm based on model-based stochastic analysis of feature correspondences in a relation vector space, which is quite robust to shape variations as well as invariant to geometric transformations. We represent an object using the ARG (Attributed Relational Graph) model with features of a set of relation vectors. In addition, we statistically model the partial occlusion or noise as the distortion of the relation vector distribution in the relation vector space. Our partial matching algorithm consists of two-phases. First, a finite number of candidate sets areselected by using logical constraint embedding local and structural consistency Second, the feature loss detection is done iteratively by error detection and voting scheme thorough the error analysis of relation vector space. Experimental results on real images demonstrate that the proposed algorithm is quite robust to noise and localize target objects correctly even inseverely noisy and occluded scenes.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.9
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• pp.56-65
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• 2005

A dynamic analysis method that freezes a time domain by discretization and solves the spatial propagation equation has a unique feature that provides a degree of freedom on spatial domain compared with the space discretization or space-time discretization finite element method. Using this feature, the time finite element analysis can be effectively applied to optimize the spatial characteristics of distributed type actuators. In this research, the time domain finite element method was used to discretize the model. A state variable vector was used in the discretization to include arbitrary initial conditions. A performance index was proposed on spatial domain to consider both potential and vibrational energy, so that the resulting shape of the distributed actuator was optimized for dynamic control of the structure. It is assumed that the structure satisfies the final rest condition using the realizable control scheme although the initial disturbance can affect the system response. Both equations on states and costates were derived based on the selected performance index and structural model. Ricatti matrix differential equations on state and costate variables were derived by the reconfiguration of the sub-matrices and application of time/space boundary conditions, and finally optimal actuator distribution was obtained. Numerical simulation results validated the proposed actuator shape optimization scheme.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.350-350
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• 2017

저수지의 설계홍수량 산정 시 인근의 기상관측 자료를 활용하고 있으나 인근에 기상관측 자료가 없거나 저수지 배후 유역이 큰 경우에는 단일 기상관측 자료를 이용하기에는 한계가 있다. 따라서 실무적으로 지점별 기상관측소의 자료를 이용하여 설계홍수량을 산정할 때에는 각 관측소 자료를 이용하여 확률강우량을 산정하고 Thiessen 가중평균을 한 후 면적우량환산계수 (ARF)를 곱하여 사용하고 있는데, Thiessen 방법의 경우 방법이 간단하지만 지형 고도 효과는 무시되고 우량계의 지배면적에 의한 우량계의 분포 상태만을 고려하게 된다. 그러므로 설계홍수량 산정시 사용되는 Thiessen 방법은 공간적 불확실성을 내포하고 있고, 특히 소규모 저수지의 설계홍수량을 산정하는 경우에는 저수지 유역의 국소적인 특징을 나타내기 어렵다. 본 연구에서는 설계홍수량 산정 시 저수지 위치에 해당하는 확률강우량의 공간적 불확실성을 평가하기 위하여 SIS(Sequential Indicator Simulation) 방법을 이용하였다. SIS 방법은 Kriging 기법과 마찬가지로 베리오그램으로부터 얻어지는 공간적 상관관계를 기반으로 하고 있는 방법으로 Kriging 기법과 달리 공간분포의 국소적인 특성을 평가할 수 있다는 장점을 가지고 있다.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.267-273
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• 2017

With the development of various devices and communication technologies, the production and distribution of various multimedia contents are increasing exponentially. In order to retrieve multimedia data such as images and videos, an approach different from conventional text-based retrieval is needed. Color and shape are key features used in content-based image retrieval, which quantifies and analyzes various physical features of images and compares them to search for similar images. Color and shape have been used as independent features, but the two features are closely related in terms of cognition. In this paper, a method of describing the spatial distribution of color using a complex color model that projects three-dimensional color information onto two-dimensional complex form is proposed. Experimental results show that the proposed method can efficiently represent the shape of spatial distribution of colors by frequency transforming the complex image and reconstructing it with only a few coefficients in the low frequency.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.2
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• pp.402-419
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• 2014

This study attempts to investigate the spatial characteristics of private tutoring markets for adults which have been expanded rapidly with labor market changes in Korea. In particular, For the purpose, we examine thoroughly various indies of labor markets and private tutoring markets for adults in Korea in first and then analyze the spatial characteristics. We classify private tutoring institutes for adults into two categories by job-statuses and education levels, and analyze the spatial distribution patterns of the attendants of the classes. In order to understand the spatial characteristic of their distributions, we distinguish whether there exist the spatial autocorrelation or not by applying Moran's I values for each categories in first. We also examine the spatial cluster patterns by Hot spots analysis utilizing $G^*$ statistics. Multiple linear regression models are developed for each category to explain the relationships between the spatial distributions of private tutoring institutes and geographical variables.

• Information and Communications Magazine
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• v.33 no.9
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• pp.3-7
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• 2016

딥러닝 기술은 수많은 입력 데이터에 내재하고 있는 특징을 추출 및 합성함으로써 복잡한 특징공간을 모델링할 수 있는 강점을 가지지만, 테스트 환경에서 나타날 수 있는 특정 데이터 분포에 대하여 일반화가 잘 되지 않을 경우에는 해당 데이터를 이용하여 주어진 환경에 모델을 적응시킬 수 있는 기술을 필요로 한다. 이 글에서는 DNN 모델의 adaptation 기술 연구가 가장 활발하게 진행되고 있는 음향모델링에서의 다양한 adaptation 기술을 통해 연구 동향을 알아본다.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.4 s.304
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• pp.43-50
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• 2005

This paper proposes a new pattern recognition system combining the new adaptive feature weighting based on the genetic algorithm and the modified KNN(K Nearest-Neighbor) rules. The new feature weighting proposed herein avoids the overfitting and finds the Proper feature weighting value by determining the middle value of weights using GA. New GA operators are introduced to obtain the high performance of the system. Moreover, a class dependent feature weighting strategy is employed. Whilst the classical methods use the same feature space for all classes, the Proposed method uses a different feature space for each class. The KNN rule is modified to estimate the class of test pattern using adaptive feature space. Experiments were performed with the unconstrained handwritten numeral database of Concordia University in Canada to show the performance of the proposed method.

• Journal of the Korean association of regional geographers
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• v.17 no.1
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• pp.122-139
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• 2011

Yanbian area is a region with great interests to Cultural-Historically Korea as well as China. Cultural-historic study on Yanbian are lots of researches but can find few mapping for sites. This study aimed to make a map and analyze characteristics of distributions in the Cultural-Historic sites of Yanbian using Google Earth. We made a distribution map from stone age to Qing Dynasty. Symbology for mapping made color symbols by time series and categorical symbols. As a research finding, Sites of Balhae and Yuo-Geum age account for large parts in comparison with other ages in Yanbian. Especially, sites of Goguryeo, Balhae and Yuo-Geum age showed spatio-temporal structure of accumulative layers Characteristics of distributions is located in basin and stream area in the early age, and after then historical period moved to hilly sides and mountainous areas. The result of this research is expected to offer information for relevant follow-up studies of Cultural-Historic sites.