• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2003년도 춘계학술대회
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• pp.97-108
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• 2003

Cluster analysis has been widely used in many applications, such that pattern analysis or recognition, data analysis, image processing, market research on on-line or off-line and so on. Clustering can identify dense and sparse regions among data attributes or object attributes. But it requires many hours to get clusters that we want, because of clustering is more primitive, explorative and we make many data an object of cluster analysis. In this paper we propose a new method of clustering using sample based on grid. It is more fast than any traditional clustering method and maintains its accuracy. It reduces running time by using grid-based sample. And other clustering applications can be more effective by using this methods with its original methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.130-132
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• 2005

This paper presents two ART-based neural networks for the identification of gas mixtures subject to the drift. A fuzzy ARTMAP neural network is used for classifying $H_2S$, $NH_3$ and their mixture gases including a reference gas. The other fuzzy ART neural network is utilized to detect the drift of a tin oxide gas sensor by tracking a cluster center of the reference gas. After detecting the drift, the previous cluster center of each gas is updated as much as the drift of the reference gas. By the simulations, the proposed method is shown to compensate the drift on-line without making many categories of target gases compared with the previous studies.

• Journal of Electrical Engineering and information Science
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• 제2권6호
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• pp.191-196
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• 1997

Fuzzy clustering has been playing an important role in solving many problems. Fuzzy c-Means(FCM) algorithm is most frequently used for fuzzy clustering. But some fixed point of FCM algorithm, know as Tucker's counter example, is not a reasonable solution. Moreover, FCM algorithm is impossible to perform the on-line learning since it is basically a batch learning scheme. This paper presents unsupervised learning networks as an attempt to improve shortcomings of the conventional clustering algorithm. This model integrates optimization function of FCM algorithm into unsupervised learning networks. The learning rule of the proposed scheme is a result of formal derivation based on the gradient descent procedure of a fuzzy objective function. Using the result of formal derivation, two algorithms of fuzzy cluster analysis, the batch learning version and on-line learning version, are devised. They are tested on several data sets and compared with FCM. The experimental results show that the proposed algorithms find out the reasonable solution on Tucker's counter example.

• 한국대기환경학회지
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• 제33권6호
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• pp.593-604
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• 2017

The suspended particulate matter(PM) was measured in subway tunnel of Seoul Line 1 to 9 in order to evaluate the pollution degree and characteristics of the PM in the subway tunnel. Also, to analyze the effect of outdoor aerosol concentration on the PM concentration of subway tunnels, the ambient PM concentration around the subway station was extracted by spatial analysis using $PM_{10}$ data of Seoul air pollution monitoring network. Finally, in order to understand pollution pattern in the Seoul subway tunnels, cluster analysis was performed based on input data set such as PM levels in tunnel, tunnel depth, length, curvature radius, outdoor ambient air pollution levels and so on. The average concentration of $PM_{10}$, $PM_{2.5}$, and $PM_1$ on subway tunnels were $98.0{\pm}37.4$, $78.4{\pm}28.7$, and $56.9{\pm}19.2{\mu}g/m^3$, respectively. As a result of the cluster analysis, tunnels from Seoul subway Line-1 to Line-9 were classified into five classes, and the concentrations and physical properties of the tunnels were compared. This study can provide a method to reduce PM concentration in tunnel for each pollution pattern and provide basic information about air quality control in Seoul subway tunnel.

• 한국환경복원기술학회지
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• 제13권3호
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• pp.36-45
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• 2010

To analyze the relationship between climatic factors (monthly mean temperature and total precipitation) and tree-ring growths of Quercus mongolica Fischer (Mongolian oak) with different topographic sites in Mt. Worak, more than 10 trees were selected from each of seven stands. Two cores from each tree were measured for ring width. After crossdating, each ring-width series was double standardized by fitting first a negative exponential or straight regression line and secondly a 60-year cubic spline. Seven stands were categorized in two groups using cluster analysis for tree-ring index patterns. Cluster I (four stands) was located in higher elevation (550-812 m) with aspects of east, west and northwest, and cluster II (three stands) was located in rather lower election (330-628 m) with aspects of north and northwest. The aspects of two clusters were not significantly different. Response-function analysis showed a significant positive response to March precipitation for both clusters. It indicates that moisture supply during early spring season is important to radial growth because the cambial growths of ring-porous species, such as Mongolian oak, start before leaf growth. Cluster II showed a positive response to the precipitation of middle and late growing season, too.

• 한국콘텐츠학회논문지
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• 제10권7호
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• pp.49-54
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• 2010

인터넷 환경의 급속한 발전과 더불어 국내외 미션 크리티컬한 비즈니스 환경이 온라인에 의해 서비스 되고 있다. 따라서 웹 환경을 통해 처리되어야 할 정보의 양의 급증과, 이의 처리를 위해 여러 개의 단일 서버를 고속의 네트워크로 연결한 고가용성 구현이 가능한 클러스터 컴퓨팅 시스템이 등장하게 되었다. 그 결과 클러스터 기반 DBMS에 관한 연구와 상용화된 솔루션을 통해 국내외적으로 활발히 진행 중이며, 이에 따라 클러스터 기반 DBMS를 효율적이고 최적화된 상태의 관리 연구는 미흡한 실정이다. 따라서 본 논문에서는 클러스터 기반 DBMS를 위한 고가용성 클러스터 솔루션의 최적화된 관리 기법과 이론에 대해 알아본다.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2005년도 27회 하계학술발표회 논문집
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• pp.116-139
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• 2005

ICT(information and communication technology) has played a pivotal role in the world economy, and the out look for ICT has improved markedly. One of the noticeable characteristics in the ICT sector Is the global rationalization of its technology and service. Specialization on the specific ICT capability is a pressing problem for many countries. Along the line of classical innovation cluster and network studies, this paper suggests a way to find and analyze the role of core technologies on the ICT network First, technology network is constructed by using patent citation data from USPTO. Then, a couple of cluster is generated by K-means clustering technique. Finally, brokerage analysis is applied to manifest the role of principal technologies. The network visualization and some stylized facts on dynamics are briefly given altogether Based on the role and relationship of technologies across clusters, it is expected that this research could contribute to the ICT cluster formation and the vision-making for ICT specialization at the viewpoint of technology Policy.

• 천문학회보
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• 제39권2호
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• pp.67.1-67.1
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• 2014

Abell 2537 has been regarded as one of relaxed galaxy clusters because the X-ray emission is regular and symmetric, while there is also evidence to the contrary that the brightest cluster galaxy (BCG) is offset from the velocity center. To investigate the dynamical state of A2537 we obtain the redshift information of cluster galaxy candidates using Hectospec mounted on the MMT 6.5 m and compile those in the literature. The velocity distribution of member galaxies appears bimodal, with the main peak including the BCG and a secondary peak at velocity difference ~2000 km s-1. Based on the three-dimensional analysis and statistical tests we conclude that A2537 has at least two substructures and is not fully relaxed from a merger near the line-of-sight. We discuss more about the dynamical state of A2537 based on the color-magnitude diagram and X-ray scaling relation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.41-44
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• 2002

The Semiconductor Industrial are developed after 1940. It was called “Rice of Industrial”. It needs great effect in Electronics. It was developed highly in recent several years with semiconductor manufacturing equipments. Semiconductor manufacturing devices are developed “In-line” type in the first stage. But It was non-effective in modem many type process. Because this reason, Cluster type manufacturing equipments are proposed. Cluster have ability of many-type-process and effective-scheduling by circular type process chamber In this paper. we propose a real-time 3D monitoring and simulation of this semiconductor manufacturing equipments. By proposed monitoring method, we have capability real visual maintanance & virtual simulation. This effective visual 3D monitoring could apply another dangerous environment in entire industrial.

• Journal of Astronomy and Space Sciences
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• 제17권2호
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• pp.125-132
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• 2000

Long-slit spectra, covering the wavelength range 4050~5150$\AA$, have been used to investigate the radial behavior of absorption line features (G4300, Fe4383, Ca4455, Fe4531, Fe4668, and H$\beta$) along the major and minor axes of the bulge of M104. The heliocentric recession velocity of M104 has been derived as 1260$\pm$190${kms}^{-1}$. The strength of a number of metal absorption lines is decreasing with increasing radius, and the minor axis shows much steeper radial line gradients than the major axis. Line index of H$\beta$ has an opposite trend to other metal lines, i.e., increasing outward. The results in this paper imply that the properties of absorption line index distribution in M104 bulge have in many aspects similar trends to those of elliptical galaxies.